#1
i have a pack of guitar strings that was given to me for a les paul but i need strings for my fender,

so do all guitar strings fit in any guitar?
#2
Well, electric strings will fit most electrics. But some string gauges work better with different instruments. For example, you'd generally want light strings on a superstrat to improve noodling, in the same way that you'd want heavy strings on an archtop to improve jazz tone.

What gauge are the strings. If they're a 9-42 or a 10-46, or even an 11-48, they'll be fine for either.
#3
well they must be electric guitar strings, if they are, then yes

Epiphone Les Paul Standard Plus-Top, SH-2 and SH-5
Ibanez GRX20
Baron Acoustic
Peavey Valveking 112
Roland Cube 15
Dunlop Crybaby From Hell
Dunlop GCB-95 Crybaby
Boss MT-2 Metal Zone
Boss PH-3 Phase Shifter
Boss BF-3 Flanger