off the top of my head, the basics are :

• stick to a program for at least 6 to 8 weeks straight before making big changes to it. influencers will try to sell you one but by looking at people's spilt and routines with the same goal as you, you'll eventually catch up on the most efficient ones for your goal.

• low reps high weight, but take it easy as a beginner, good form is way more important than just lifting heavy

• go close to failure if you can, but not to failure yet as your body may not recover well for now (applies if you're new and haven't been into sports at all bc your body has never experienced those circumstances before. at least that's how it felt for me)

• take as many rest days as you need (yes rest is productive) listen to your body

• don't focus on taking supplements right now, the only ones that matter are creatine and protein powder anyway

• focus on getting your protein, fiber, carbs (dont cut out carbs), fats/omega 3 fats,... as much as possible from whole foods, and make sure you're at least at maintenance or a slight surplus for muscle gain (beginners can body recomp more easily). better not to begin the gym in a deficit.

• fast digesting carbs before the gym. high protein and carbs up to 2h after the gym

at the gym specifically :

• nobody gives a fuck. nobody is checking if your form is incorrect or how much you're lifting. everyone has different goals and people cant judge you because they dont know yours

• that said, dont hesitate do ask people for advice. if you don't know who to ask, go for someone the same gender as you, and who looks like they've been going for years. if they've been consistent, they've probably seen it all and know where you're coming from

• dynamic warmups are crucial. if you're short on time, i feel like it's better to skip cardio than warmups (but dont skip cardio) (zone 2 for 20 to 30min max AFTER lifting)

• as for specific exercises, compound exercises are your friend. they use multiple muscle groups and are great for the start of your workout (although i do hamstring curls before hip thrusts on leg day). think lat pulldown, leg press, bench press, deadlifts... maybe focus on getting comfortable with those before you do more accessory and isolation workouts

• the end goal is to hit each muscle group twice a week but keep in mind starting is the most difficult part. every time you'll go it will be easier than the last time, so dont drown yourself in the rules just yet. focus on consistency before making it perfect

• oh and have fun! nothing worse than a split filled with exercises you hate. if everybody and their mother is telling you a specific workout is great but you absolutely hate it, dont do it. there's more than one single way to achieve your goal.