The only problem with learning MMA is that there is literally too much information for a new guy to take in. It takes a while to get really good and you should train some of the arts individually before you start to try and put them together. Fighting MMA is an advanced system and it is usually for guys who have some sort of base art.
The reason this is an issue is because, you will be trying to learn how to box, kickbox, grapple, wrestle, takedowns, submissions, throws, etc.....there's so much to learn that its really hard to just start in MMA. What will most likely end up happening is that you'll probably won't be that proficient at any one aspect of fighting and will get owned by someone who is somewhat of a specialist in something.
For instance, a great striker will take you out on the feet before you even get a chance to do much because your striking will be sub-par or mediocre at best.
Same thing as your ground. Ground wizadry takes a long time to attain. I've been training BJJ for about 4 years now and just got my purple belt. I train all the time and try to get as good as can...the key to being good on the ground is lots of mat time.
This is ofcourse grappling without punches....once you start adding in punches, you'll see the bigger picture. It's hard enough to hang with someone who is just grappling, but its very hard to roll with someone who knows how to roll and punch on the ground.
I would start with some Muay Thai and some BJJ. Learn those techniques and start from the bottom....be patient with your progression and try to learn as much as possible. Ask questions and grow as a fighter and as an individual.