If you don't have any frosts or cold snaps coming up (like me) stick it outside and let live. I would research all you can about your plant first, and know when to repot it. When it is time to repot it, plant it in a grow box (made out of wood, square generally shallow but allows the roots to grow to the side), or a large black nursery pot. Keep it in that for about 3 years (or longer depending on how fast the trunk thickens), and then you will have something nice to work on.
If you don't want to wait 3 years, you can go to Home Depot and buy some $5 garden junipers, and practice techniques on them that you learn. You can have one tree that you work on for wiring, one tree that you practice your pruning on, and maybe another tree you can just observe to see the growing style. Don't worry if these $5 trees die at all, they're not supposed to live.
I agree, join a club in your area. You will then have ready access to quality bonsai supplies (usually at lower than market prices), access to raffles to buy plants that people are passing on, along with winning pots, stands, and other bonsai essentials. You will also have the experience along to go with you, and you make new friends along the way.