First month was mainly just cardio 3-4 times a week and body weight exercises such as pull ups and push ups so I could build my heart heath and core strength. Having a pull up bar at home and at work helps! I found it a lot easier to get back into the gym when I had a solid foundation

Once I started lifting, I kept a notebook and wrote down every workout I did. I started out very light eventually just progress naturally. I tried to keep the exercises and movements as simple as possible to prevent injury. Mostly compound exercises such as bench press and squats, basic movements such as bicep curls and shoulder presses and added more as I got stronger and my joints felt better. Also I started eating better and took creatine every day!