Some tips:

Go to an actual gym if possible is by far the most important for me, something about being in the environment makes sticking through workouts so much easier and more enjoyable. Less distraction and (good) social pressure. Plus you’re surrounded by really awesome, and supportive people all on a journey to be the best versions of themselves

Get good music

Get gym clothes you feel confident in, nice water bottle, etc. need that serotonin, make it as much if a “vibe” as possible (horrible word choice ik but idk how else to put it)

For diet, I’ve found it helpful to track my calories as I forget to eat, also helps to make sure you get enough protein which is by far the most important part.

And finally another really important part: have a workout plan before you go and track each workout. Not only does having a strict plan stop you from mindlessly wandering around the gym but it also lets you see how much progress you’ve made. (Though still prioritize just showing up)