Most bicycle wheels will have rim tape covering the spokes or spoke holes if a double walled rim. Which is common today. Lower end bikes from the vintage days did tend to come without such or used a rubber strip that by now will have long since rotted and fallen off.

If you have a rim that the spoke nipples are exposed on the inside, then you should definitely use rim tape or perhaps fashion another strip of rubber from a old inner tube to cover them. If any of the spokes are protruding from the nipples, then that needs to be addressed before you install the tape.

If it's a double wall rim and the spoke nipples are not exposed, then it also needs tape or maybe one of the inserts made for some rims.