I'd like to use this mountain bike to learn how to ride on the trails. There is a trail close by for beginners and I just want to make the bike as safe as possible to ride. Dont want my chain skipping while im climbing. After I get the hang of things then I'll sell it. Which is why I would like to hold on to the bike.

Should I be concerned about my front derailleur being compatible with new chainrings? I read on sheldon brown website that most old front derailleurs have greater compatibility or something to that effect.

What if I were to get this one?

Sunlite Crankset Sunlt CTLS STL 28 38 48X170BK4ARM WCG 21837 | eBay

The front derailleur is falcon brand