If that's all it took than everyone would squat, pull, and press monstrous numbers. To become better you MUST do more than just the lift. You must address your weakness that is causing your lift to stall which means attacking those weaknesses with assisting/auxiliary lifts and those weaknesses changes as your lifts increase.
While I agree that building weak points is important.... Just focussing on the main lifts through decent programming really does work for most guys. Look at how simple the Lilliebridge method is. That's really what they do.
I was only able to lift two days a week for a few years through grad school ( plus full time work and an internship) - I made those days count and did a lot of volume but it was 90% the main lifts, maybe even 95%
That brought me to a 2200 pound total. I made the jump to around 2500 after adding in a third day with some conditioning and more auxiliary stuff...... so, yes aux stuff helps a lot, but a lot can be achieved on basics.
But the point is that lots of guys are really putting too much emphasis on the aux stuff too early on. The OP here is a rank beginner - so while you're right about programming up your weak points I have to agree with NOV that this cat could use a few years of basics. The big 3 plus overhead press, abs, leg press, and rows.
With all that said - the most important sentence any lifter will ever hear. The best advice I ever took.... Go find a team. Go find the best guys in your area and start training with them. Ask around, go to meets, or ask online if anyone knows a crew in your area.... but there's always a crew within an hour's drive. Go there and do whatever they do. Even at my point in the game, after hitting a few pro totals I stalled out. I realized that I spent the year thinking that I knew better than anyone else and got away from what my team built me with. Now that I went back to shutting my mouth and doing what I'm told my lifts are all going up.
