You can read these novels that people post but the BIGGEST thing stopping you is this:
If you cant motivate yourself to go to the gym on a set routine you are not motivated enough to get big.
1) just start going, you won't enjoy it at first and it will be awkward but just put on beats and remember why you're there.
2) start with a full body work out using the pin/plate machines, do one exercise for each muscle group. Warm up set of light weight then 3 sets of 8 reps of the weight your doing.
3) Mix it up. say you go 3 days a week, do a different back/shoulder/chest etc. exercise everyday.
4) get a small notebook, THIS IS THE BEST THING FOR YOUR WORK OUT. Keeps you on the right track and seeing your progress just motivates you more
5) Only do as much weight as you can get your 8 reps with, start doing to many and your form goes and you will not make any gains. Form, Reps, & Exhaustion over weight. Leave ego at the door
6) Observe. When I started lifting I would just people watch and learn new exercises and ways to work muscles. This is big.
7) Read online about more workouts and different things to do.
Once you have a base and feel comfortable start working out a muscle group per day
PM if you have questions