If you've not been shown "how to tune" a peg style instrument, you really should get someone to show you the technique. (At least according to experts I met in my youth.) You need to "loosen" the peg just a bit when you start to tune, turn it to pitch and then "seat it" with a slight press into the hole for best results. If you try to push the peg in to where it holds while turning, you may ream out the peg holes so that maintenance will be required a lot more frequently.

A nephew who borrowed an old fiddle I had rebuilt ($10 from a garage sale) completely destroyed the peg holes in a little less than one school year through not being shown how. (Or maybe he thought it would get him out of the orchestra if he broke it?)

Opinions vary, but most players I know also keep a stick of "peg dope" in the case so that any time they change a string they can wipe a smear of it on the peg. It doesn't take much, but will make the peg action smoother. Since you have to take the peg out to get the dope where it's needed, it is just an occasional thing.

If you're not experienced (or just not currently practiced) at fiddle tuning, you may want to consider "fine tuners" on all the strings. Classical players generally(?) use them only on the top one or two strings, but lots of "folk" fiddlers use them on all four. They're often recommended for young students on all strings - at least around my neighborhood - since the little ones have a harder time holding the peg torque accurately (and often have poorly setup instruments?).

John