The only way to build up is to stick to it and read all the free info on exercises on the net in books from library etc. If your really desperate you can even try your luck with a personal trainer just for one session to explain different exercises. Personal trainers can be a waste of mony sometimes. It is much cheap just to stick with stuff over a long period of time an read about it a bit on forums like this.
Ok in your case id go even more simple. Do below exercises either on Monday, Wednesday and Friday or Tuesday, Thursday and Saturday.
Hack squats 2-3 sets of about 6-8 reps
Barbell Hack Squat
Deadlifts 2-3 sets of about 6-8 reps
Barbell Deadlift
Bench Press 2-3 sets of about 6-8 reps
Barbell Bench Press
An example:
Monday
Hack Squats
Deadlifts
Bench Press
Wednesday
Hack Squats
Deadlifts
Bench Press
Friday
Hack Squats
Deadlifts
Bench Press
I hope that makes sense and helps you better than my previous advice. Hack Squats will be better for you if you dont have a squat rack. With deadlifts make sure the barbell is really close to you legs when you lift it the further away from your body the more likely you are to hurt yourself. Its ok to even be touching your legs as it comes up and goes down.