If you accept practicing only at one-half to a full turn, you can have a lot of fun, and gain a lot of skill, with a light setup. With practice, you'll find that you can hit a surprisingly small target at light-knife ranges. This will allow you to place your aiming-marks close together, and to throw a lot of knives into the target. For one thing, they're not necessary at ranges of only a few feet. Finally, safety considerations in a confined space call for restrained throwing.
Eye protection is a terrifically good idea.
The small size of the equipment used in light knife throwing makes it a very flexible sport. Light knife throwing can be practiced in a basement or garage, or on a small patio, or in a tiny back yard. Because even a large cardboard target will weigh only a few pounds, you can change your throwing venue simply by carrying your target to a new place. Check your luggage through. A plain carboard box will stay in one piece long enough for an hour's throwing with icepicks or light knives.