I had trouble with F's and barre chords the first time that I tried to learn to play. I have recently picked it up again and a friend told me to take my old guitar into the shop and have it "set up", this should run $30-40 with new strings, all in. You might be able to get it for less, you shouldn't pay more. Most commercial places charge the same for acoustics, acoustic electric and full electric, even though the electric are a lot more complicated.

The action on your guitar may be too high to be comfortable. In other words, the stings are higher off the fret board then they need to be, making it harder than normal to hold them to the frets and make clean chords. The tech will belt sand the back of the saddle and put it back in the bridge, he may also adjust the nut and tighten or loosen the truss rod to get everything as square and comfortable as possible. Tell him you're a beginner and want light strings with less tension and he'll put something on that hurts the least.

I you're not sure if this is a solution, try an electric guitar out if you know someone that has one or try one at the guitar store. Or try a nice silky Martin or Taylor while you're at the guitar store. If it is easy for you to do the "F" with one of these guitars, then you just need to get yours adjusted (called a "set up"). It should take the store 15-30 minutes to do it and they'll clean your guitar, put new strings on it and check it all out.

Of course, you'll also need to practice, practice, practice.