I have been reading about action and discovered the reason my A string has a buzzing sound afterwards is because the action is too low. So I have a few questions:

Can I fix this myself or do I need a professional?
Would it be covered under my warranty?
Will fixing it and making the action higher make it more difficult to learn? (I am a beginner of 7 weeks practice)

Thank you.
It's a pretty easy job to change and it wont affect warranty at all. As long as you raise the action small amounts it wont suddenly become hard to play, only if it's too high (and how high is often down to preference). How hard it is to change depends on the type of guitar
If its an electric you can raise your bridge some, otherwise your better off asking a professional.

Your warranty *may* cover setups. If you haven't had it setup you probably should and your warranty might cover it since that's almost along the line of "Defect"

Lets see... higher action does make it harder to play, but its easier to play because you aren't having the buzzing. If you don't have buzzing then you know your fretting it right but right now your guitar is hindering that learning process for learning how to make notes ring out and fret the strings properly. So in that sense it will make it easier to play.

If you have it setup right you wont have to worry about it being harder, it will be "Just right."

You might try putting on medium strings onto your guitar instead too. Lighter strings have a higher potential to give fret buzz, so if you have custom lights or even lights on it that might be why you are getting the buzz now.

On an electric the action isn't too big of a difference because the strings are so easy to press down. On an acoustic it would probably make doing barre chords a pain though.
It is a generic, cheap, Squire Strat. I got it in a package that had an amp and picks and some other items I don't really know what are for but one of them is probably for this.
for a strat, the string saddles at the bridge should have one little bolt at either side of the saddle. how tight you screw these bolts in will effect how high your action is

bolts futher in = higher action

bolts screwed out a little = lower action

Epiphone Hummingbird
Epiphone Futura Custom Prophecy (Twin EMG)
Vox Valvetronix VT20+
Vox Wah
Boss MD-2
Danelectro Cool Cat Drive
Boss EQ

you can do it if you wanted, i had to do do it with my epiphone s-310 strat. doesn't take that much effort, simply a crosshead screwdriver and about 10 minutes tops.
just loosen the strings, make the bridge higher, or even adjust the saddle on the a string. but id suggest just the bridge. then tune in (as loosening the strings would have de-tuned them) and try it out. if still buzzing, try once more. if still fails take it to a music shop and tell them to sort it.