While my preference is for beginners strength trainees to start off on a 3 day programme, it's certainly viable to make decent gains for a while on two days. As long as you push yourself on these days, and take care of your sleep and nutrition, you'll be fine.
The most important thing is to pick days that suit your schedule, so as to remove any chances of missing a session.
The ideal approach is to have two days between sessions 1 and 2, and then 3 days of rest before starting the next week. Therefore some acceptable approaches would be to train:
Monday | Thursday
Tuesday | Friday
Wed | Sun
I would strongly recommend trying to keep training to the week days if you can. Be honest with yourself: is there a chance you're going to be hungover sometimes on a Saturday? Then let's not plan to train then.
All of the above exercises are done with a barbell (the exception being chins/rows). The bar is the most efficient way of progressively loading the basic movement patters of squat, push, and hinge.
These are the best 'bang for your buck exercises'. Yes there is a place for single leg this and core that, but you don't need to do that kind of stuff until you're strong on the basics. Adding 50kg to your squat and deadlift, and 25kg to your bench and overhead press, is going to do far more for your physique, performance, and health.
So in short - no, you can't sub goblet squats for barbell squats, or kettlebell deadlift for barbell deadlift. Stick to the programme.
Oh, and OHP stands for overhead press.
Squat Tutorial (still working on my own vid!)
A good rule for any kind of training is to 'start too light'. I'd go as far as to recommend you just start with the empty bar on everything except the deadlift (you'll want plates on the bar to have it at an appropriate height).
Starting light means you can worry less about getting the weight up, and more on practicing proper technique.
How to Progress
For each of the main lifts, you'll notice you have a few sets of 5, followed by a single set of 5-10 reps.
So what's all that about?
Let's imagine it's your first session, and you start with squats. You take the empty bar and perform 4x5. Then, for the final set you go for 5-10 reps (ten being the goal). If you get the 10 reps, you're permitted to go up in weight for the next session. Anything short of 10 reps means you must keep the weight the same for the next workout. The rate of progression is 5kg for squat and deadlift, and 2.5kg for bench and overhead press. Please bear in mind that when I say 5kg, that's 5kg total, not each side. Likewise, a 2.5kg increase for bench would be a 1.25 plate each side.
This might seem like very slow progress, and it is - for good reason. Assuming you hit 10 reps every single time, in the space of 4 weeks you'll have added 40kg to your squat and deadlift, which is no easy feat. The bench and press will naturally progress slower as they are only performed once per week (a drawback to training twice per week).
Chins / Rows
You may notice that I have no sets listed for this, just '50 total reps'.
As a beginner, you probably can't do a chin-up, or at least no more than a few reps. The 50 total reps idea is one I adopted from the Wendler 531 beginner programme. Essentially you just have to make up 50 total reps, using any combination of sets and reps you want. If you can do a few chins, you'll do a few sets of those and then make up the remaining reps with some kind of a row (it really doesn't matter too much what kind). To better explain this, here's an example:
Chins 5x2 (10 total reps)
Dumbbell Row 4x10 each side (40 total reps)
If you can't do a chin-up, you have two options: perform some kind of a progression (e.g. band-assisted chins, lat pulldown, etc.), or just do all 50 reps on rows.
How long should you rest? The simple answer is long enough for you to be able to perform the next set with great technique, and getting all of your reps. For most people, this will necessitate 2 - 4 minutes of rest. Anything less than that is not acceptable. This might seem silly for the first few sessions with very light weights, but it's an important habit to form early on. Use the rest time to brush up on the technique videos I have linked.
The Deadlift: A Word of Warning
The deadlift is a great exercise because it allows us to use a lot of muscles and move more load than any other exercise. This is great but it comes with a cost: fatigue. Beginners can deadlift twice a week just fine, and it's a great way of getting frequent practice at this lift, the technique for which can take a while to get a hold of. However: At a certain point, deadlifting heavy twice per week will become too hard to recover from. It's been my observation that this usually occurs somewhere around the time they are up to approximately their bodyweight on the bar. You'll know it's too heavy becasuse you'll struggle to add weight on the second session and your low back may feel very fatigued. At this point you need to immediately drop the deadlift from one of the days (doesn't matter which).
On that day you can instead begin doing some lighter posterior chain work (RDLs, back raises, glute ham raises, etc. for a total of 50 reps). I'd recommend moving these to after the bench or press. Supersetting them with bench/press or the chins/rows is also acceptable.
Plateaus / Moving On
As with all programmes, this won't work forever. You will eventually find that you need to reduce your jumps on the lower body lifts to 2.5kg.
If you hit a sticking point, my advice would be to reduce your weights by 20% and start working your way back up again. Also ensure you address your sleep and nutrition. This is by far the number one reason I see people hit plateaus. Here's what that might look like for the deadlift after a couple months into the programme:
70kg 2x5, 1x10
75kg 2x5, 1x10
(starting to get hard, so trainee moves to 2.5kg jumps)
77.5kg 2x5, 1x10
80kg 2x5, 1x9
80kg 2x5, 1x6
(trainee feeling very fatigued so resets by 20%)
65kg 2x5, 1x10
70kg 2x5, 1x10
75kg 2x5, 1x10
80kg 2x5, 1x10
82.5kg 2x5, 1x10
85kg 2x5, 1x10
87.5kg 2x5, 1x9
87.5kg 2x5, 1x8
If you hit a second plateau, I recommend moving to 3 days per week, as you likely just can't fit enough training stimulus/stress into two days to continue driving strength gains.