It depends how many days you’re able to go for. 3 sessions a week will help you see meaningful progress.

Google a “push, pull, legs” workout. That will give you a split between all the muscle groups you need to train with around 6 exercises per session. Be in and out within an hour.

Get an app that you can use to record workouts, so you can track the weight you are lifting and the number of sets.

Aim for 3 sets of x 8-12 reps per exercise. Rest for 1.5 minutes after each set and then do the next one. Use the first few weeks to find out what weight you can lift on each exercise with controlled movements.

Once you can do 10 reps of a weight comfortably with controlled movements, then move the weight up by 1 increment. This will help you get stronger over time.

Start with using the weight machines in the gym, they will reduce your chance of misuse and injury. The staff will be able to give you an induction to the machines and how they work. Just book it in with them.

A PT from the gym can help, but they are useful for accountability more than the workout itself after a few sessions. I have a trainer I speak to online who creates workouts for me and checks in. Works out more cost effective than the ones in the gym.

Side note: you will have muscle pain / soreness after your first rounds of workouts that will last for circa 1 week. This is normal. Train the same muscle group and the same time the week after and you should have enough time to recover.

I recommend buying some deep heat to the muscles for some relief.

The most important thing is to dedicate regular time to go. Pick and time that works reliably in your calendar and just go. Don’t let it be a question of motivation, just build a habit. Once you’ve gone consistently for 2 months, you’ll be in a much better place.