Depends on what stain you want and how to achieve it.
You are likely to need to sand the original finish all the way off, then sand smooth, then stain and then use multiple coats of Tru oil/gun oil over the top to get a Matt or a glossy finish.
With a block colour, you can still sand back lightly, but not to bare wood, the paint just needs somewhere to stick to. Use a Nitro spray can, probably better to use a primer first partly to prep, but partly to get used to the technique of spraying, then your colour with as many coats as you need and buff. If you use a metallic finish you will probably need a clear lacquer on top.
Both take their time in various ways. If you haven’t got a Graphite paint shielded cavity/pick up rout, may as well do that at the same time, that will make it awesome