The biggest question is whether you should get an inkjet or a laser printer. It depends on your needs. If you plan on printing a lot, the toner in laser printers lasts a long time, but the replacement ink can be pricey. The color on laser printers is much more vibrant than an inkjet. However, inkjet ink is relatively inexpensive but plan on replacing it often. Inkjets also print photos better, so if you use photography in your printables, that is something to consider.
Another handy tool for printable assembly is a score board. You'll use it to make creases in paper for easy and precise folding. Don't feel the need to buy all these items at once. It takes time to acquire all the tools for printables, but in the end, you'll find that the investment will be small for a fun and creative hobby or business in printable design.