I was just about to ask what guitar are you using and do you have small hands when I read your last line.

The reason I ask is that IME some acoustic guitars with larger neck dimensions and wide string spacing can be more of a stretch (difficult) to fret open C quickly in progression changes for smaller hands.

The current model Yamaha F310 has narrow 10mm string spacing which makes chording easier for both beginner and those with smaller hands. Its nut is 43mm, with a scale length of 25". Those are the same specs as my APX600 BTW. Both come fitted with 12s default. Although I suspect they had youngster friendly hands in mind when they designed that spacing, it works for me. I have relatively small hands with proportionate to hand size fingers (not long), although I take a medium in a glove size rather than a small for basis of meaningful comparison.

So that said, unless you hands are tiny as in unusually small or petite, the F310 really shouldn't be presenting a problem with fingering Open C. It's made as an entry level guitar for beginners and has as a primary design objective being an easy chording player for beginners.

If there's any chord you should be having issues with on the F310 or APX600 it's A. Very crowded with any multi-fingered form to the point that although I can finger it with either conventional or 'Justin A', I find barre A works best for me. If you can play A cleanly without muting or par muting the G string by involuntary obstruction on those guitars, your hands and fingers in particular must be definitively small or slim. I can only imagine the frustration of anyone with larger hands with playing a multi-fingered Open A on them.

Only things my experience can helpfully suggest if you're finding C difficult on the F310 are finger flexibility exercises, to (stretch) warmup before playing, and focus on thumb and hand positioning on the neck as well as exercising cognizance of your fingers curvature in positioning as you play C so you can adjust them as required, then maintain that awareness in playing until it becomes rote.

Unless you actually have a physical stretch span limitation, it's just about thinking it through, making any adjustments necessary, then repetitious practise until you get it right.