120-130 is low, frankly your current weight is fine, so you'd be better just manipulating your body compsition to a more pro-muscle state, by working to shed a bit of excess fat if any and replacing it with muscle.
Basic guidelines for training.
1. Do total body stuff, all muscle groups worked, 2 sets per muscle 8-10 reps.
2. Do this 3x a week, using compoind movmenets like Squats, Deadlifts, Bench Press etc.
3. Repeat for 4-6 weeks starting on light weights, until your body adjusts to the biomechanics of weightlfiting.
4. Add Cardio in on a couple of the other 4 days, for about 30-40 minutes. I'd go for basic steady state for now, to help get a bit more of a cardiovascular foundation, so you're then ready for something a little more taxing in the future. Cardiovascular work should mimic weightlifting work, in relation to not doing too much too soon.
This is the sort of schedule you'd be looking at.
Day 1. Weights
Day 2. Cardio
Day 3. Weights
Day 4. Day off
Day 5. Cardio
Day 6. Weights
Day 7. Day off.
This splits the 2 off days and stopes you training more than 3 days straight.
A good gym should be able to help you do something akin to this and get you off and running
As for the diet, what meals do you eat and times do you eat?