There is a lot of space between:
I want to try something else
and hopefully become a successful fighter.
I'm pretty sure you'll enjoy and have some natural ability in other types of grappling, particulalry one like judo. You might not like getting punched or kicked (most people don't) and your body and rhythm might not be inclined towards picking up striking as easily as you did wrestling, or maybe even as easily as the average person does. It's better to do something you will stick with than start something ambtious and quit.
If you are sure you want to do MMA then you should look to sign up somewhere where you can learn submission style grappling and where you can learn boxing, Muay Thai or kickboxing. This might mean there are few choices for schools in your area or that you'll need two schools. To be really blunt, it will require quite a bit of time and money.
If you're still not sure if it's a sport you want to pursue, I'd suggest signing up for the boxing/kickboxing somewhere for a very short term contract and see how you like it. If you don't then you will probably still enjoy BJJ/Judo, but you'll prefer to focus on that type of training and competition rather than MMA.
Also, check out the thread sticked at the top of this forum.