I would start searching the forum and do a lot of reading. If your stuck on a tank that's fine, I still have two. However they can be hard to keep your humidity and heat in check. We have to modify them to work well for snakes.

I would check into tubs. They are cheap so up sizing is not a big deal. They are also easy to clean and hold humidity well.

I'm not knocking tanks though but using tubs might be better for you starting out as it could save you some money that could go into a nice enclosure down the road.