Alright mate. In my opinion you'd be best off just having a look for a decent gym and getting started straight away if you can possibly afford it. The problem with getting a bag etc and starting training yourself before you've had any proper coaching is that you start teaching yourself inproper technique etc before youve even got going, and bad habits are hard to get rid of. Lack of strength etc wont be a problem, if you find a good coach he'll bring you on as you improve and your strength will grow as you train. You could train yourself for 6 months and not be in anywhere near the shape you would be after 2 at a decent gym because of the training methods and encouragement you'll get.

Hope that helps a bit, all the best

Rich