Extremely important tip for you if you’re new in the gym -
On your first day, you’re going to do some weights and exercises in there and feel really good, maybe stronger than you thought and you’ll have a lot of endurance. The following day you’ll be pretty sore, getting more sore as the day goes on. The day after that, you’re going to be so ungodly sore you won’t know what hit you. Like it will be hard to walk if you did legs, hard to bend your arms if you did biceps, hard to raise your arms if you did shoulders, etc. Its not normal muscle sorness; your muscles will be extremely tight and stiff and painful.
This is called Delayed Onset Muscle Sorness, or DOMS - https://en.m.wikipedia.org/wiki/Delayed_onset_muscle_soreness
If you work out regularly and take a month off, you’ll get DOMS when you return, but it won’t be as bad as when you first start. Once you get going in the gym regularly, you’ll be able to work out all the time without getting sore. You only get the DOMS when you take an extended period of time off.
With that said, for your first few workouts ever, you’re going to get DOMS really bad if you’re not careful. You’re going to get it a little bit either way, but you don’t want to let yourself get it full blown really bad. It really can slow down your first few weeks to first month in the gym, and can also be discouraging.
So my tip to you - get a proper stretch and warm up in before you workout (google this for lifting weights and for cardio), get a proper cool down when your workout is down (google this for lifting weights and for cardio), drink lots of water, and most importantly - do not push yourself to hard and overwork yourself trying to be the hulk in the gym when you first start out. Working out and getting in shape is a long process, not a sprint. Start slow and your first month in the gym will be way better, you’ll get more workouts in and will get stronger. Less is more is the case here in your first month. Getting DOMS all over your body in your first week is going to blow your first month.
Also, if you’re going to lift, be sure to look up proper form for your exercises. And don’t forget warm up and cool down. Preventing muscle soreness and overload is key for getting stronger over time through regular lifting.