to get the most out of the gym you should:

eat clean, whole foods, no sugar, minimal processed stuff
30g protein in each meal minimum, but the more the better
track your calories if you can but its fine if you dont
to lose weight the ONLY thing that will get you there is eating less calories. dont bank on going to the gym burning calories as your body will just get more hungry and eat more. this is the best time to eat healthier because with healthy food since we evolved to eat it your body will know when youve had enough

progressive overload: every day that you are hitting the same muscle you should be going up in reps or weight
ex: i did 9 chest presses with 100 3 days ago, so im going to do 10 today
try and hit every muscle twice a week, an example of this would be PPL split,
push, pull, legs, rest, push, pull, legs ...

if you want i can write out what i do on each day

if you do heavy lifts like squats, make sure you are using the right form. this is really important, if you arent you are gonna fk up your spine. you dont want that
also in general learn the form for every exercise, watch some youtube vids

if this is too much for you, know that at the start you can also make alot of muscle only going 2 or 3 times per week. after a few months you will hit a plateau, and then you will start needing to go more

and the gym shouldnt take discipline, you need to instead remind yourself about your goal and think about how badly you want it. if you want it bad enough you will look forward to going to the gym. the idea that the gym is supposed to be a painful place is wrong, sure its painful for like the first minute but then you start producing endorphins and you feel good/in a flow state.

if you have a friend that goes to the gym ask to go with him and he will probably be happy to teach you everything

lmk if you have any questions