what exercises do you recommend for me?

hi, quick rundown about me:
- i work in healthcare. used to be day but now on nights. 12 hour shifts with a two days on two days off schedule. on days, i walked 25-28k steps a day. on nights it's 5k or less.
- im super inflexible it's crazy, this is something id like to prioritize BUT while also building strength, if possible.
- i am on medication that makes me hella dehydrated, but i struggle with thirst and knowin or remindin myself to drink.
- i do have a smartwatch, so certain health data is available to me.
- i do have 24/7 access to a small gym with only a couple of machines and swimming pools.
- i own: dumbbells, a yoga mat, 3 levels of resistance bands, and a foam roller. i also have recovery stuff like tens units, feet soak, heating pad, massage gun... if any of that matters.
- i am freaking smooth brain and uneducated. assume i know ANYTHING about anything and you will be gravely disappointed. but i am wanting to understand better why x does y and gets z result so any and all info is helpful.
First things first, make sure to get your electrolytes in your water, then drink enough water per day. Doing physical activity will increases water loss from sweat and muscle retention
Also did you doctor approved any physical activity ? Since we don't why you're under medication.

Second, what are your goals if your start a fitness journey ?
Improves cardio ? Conditionning ?
-> Using kettlebells, h.i.i.t protocols, stationary bicycle, for example

-> Looking good naked ? Caloric deficit, abs training, lower body training etc

Ideally you should start with 1 day full body training and 1 day cardio per week (45min max) and considering increasing one or both of them if your body adapt and don't fuck up your recovery alongside your tough job and medication.

For example :
Wednesday : Cardio of your choice, could be swimming, bicycle, running, kettlebell swings etc, for ~25mins, followed by 20mins of yoga/pilates to improves balance and flexibility

Saturday : Weighlifting
Depending on your goals, you can try split squats, hip thrusts, cossack squats then deadlift variations, vertical & horizontal pulling, a bit of pressing movements if you want pectoral & shoulders muscles. Can be a rotator cuff training and spine strength training, let me know