On and off I have practised yoga for about 12 years now (I'm 52) and find it makes more difference to my physical and mental health than other physical exercise. I started with yoga P90X, then P90X2 and then P90X3 (DVD type fitness programmes, but you can find them on YouTube). I've tried classes and if I get the right one I enjoy it but generally I prefer to be alone with an onscreen class.
In hindsight the P90X series were a great progression for me.... p90X yoga is a 90 minute programme and whilst that sounds like a long time they go through all the basic moves and I find now I know all the basics and can join a class or similar of any standard (knowing the moves and being able to execute perfectly with no props are two different things). P90X 3 is the same type of thing but in 30 minutes - providing you have prior knowledge (or accept you will have to pause and rewind) it is the most yoga you can possibly do in 30 minutes and gets it done; its my go to programme. Tried hot yoga, it's OK but expensive with no obvious benefit to me.... tried pilates and really didn't like it but it's personal preference I suppose.
Havent practised for a few months and I'm coming to miss it, pulling together a new programme at the moment which will include yoga 1-2 times a week, not just for the increased flexibility but its the closest I can get to meditation (plus it improves my pop up whilst surfing :)).
Happy to answer any specific questions if I can (I am by no means an expert) but the above has been my journey.