push ups - a lot of variants
butterflies with dumbbells lying on the ground
pullover with dumbbell (need some bench or chair)
and this https://www.youtube.com/watch?v=byxD_y2e_L8
one arm dumbbell rows
sumo deadlifts with kettlebell
lying back extension
shoulders shrugs dumbbells
Obviously, you should make sure you're warmed up before attempting any of these.
I can do you one better, I'll give you full body training in 4 minutes! Enter, the tabata protocol (thank me later).
Honestly, Dan John does a much better job of explaining it than I can. I believe he now only recommends front squats, so I'll use that as an example (...
You experience the most growth when you start working out because your body is not used to it. In a way, you experience the most “difference” during that time. You can become stronger not only through hypertrophy but also neural adaptations (https://www.scientificamerican.com/article/how-does-exercise-make-yo/).
As you workout for a longer period of time ...
I noticed that I was getting stronger each day and I built some muscles. [...] After those 2 years, I thought I should level-up myself, from beginner to intermediate level. [...] Yep, I just learnt how to bench-press last 3 months.
I think part of the problem here is that you prematurely levelled yourself up. For starters, if you've just moved from machines ...
In order to get stronger you should generally train each muscle 2 or 3 times a week with at least one day of rest in between. There are some exceptions to this guideline. For instance the deadlift can be trained once a week. However it is a good general guideline, and I believe it is where you are going wrong in your training.
So if you want to do your 3 ...