I started boxing in 2012 and haven't looked back since then. I love the sport, and you end up meeting people who are very different in terms of careers and social status, from what you (we) are. There is also a "brotherhood" type vibe to Boxing in particular (I think this is also true for other combat / martial arts type activities) and I've made many close and interesting friends (male and female).
When I first met my trainer (a current professional boxer), the 1st question he asked me was "Are you a Computer guy?". I asked how he knew and he said "You crouched shoulders are a dead give-away. We can straighten that in 3 months".
I do strength and conditioning 2 x a week, weights 1 x a week and boxing training (drills) 3 x a week and sparring with headgear 2 x a month.
5 years later, my shoulders are very straight, my hands and wrists have become stronger from punching. I've totally lean-ed out -- was healthy BMI to begin with, still lost 15 pounds in the 1st 3 months of beginning boxing. I'm also able to focus more at work.
I tried doing things separately (ex: running outside, going to 24 hour fitness just for weights etc) and it didn't work.
With this, there is 1 place I go to - my boxing gym - and get everything in the same place. My gym has TRX classes 2 x a week for strength and conditioning, in-house trainers to learn boxing 1 on 1 if you want to as well as group classes for boxing drills and heavy bag workouts.
If you do end up starting with physical exercise, be sure to also watch your diet. Also start slow and build up otherwise you may not stick to it. I started going once a week for 1 month, then 2 x a week the 2nd month, then 3 - 4 x a week the 3rd month. Now I go 5 to 6 x a week.
Exercise + Diet = Lifestyle.