Eventually you might want to get a better guitar. But your Fender should be easy enough to set up yourself. The two fattest strings are more prone to buzzing because the oscillation pattern of those strings is wider than the thinner strings.
Changing the string gauge in either direction (heavier or lighter) could potentially contribute to such a buzz. Heavier strings will have an even wider oscillation pattern and lighter strings may sit farther down in the nut slot and thus be closer to the frets. Also lighter strings have less tension and may allow the neck to become flatter (see below). Either way raising the saddle height (at the bridge) a tiny bit on those two strings should eliminate the buzz.
Adjusting the truss rod is not that difficult as long as you do it carefully and in small increments and allow time between turns of the truss rod for the neck to adjust. If you decide that a truss rod adjustment is in order, this should be done before adjusting the intonation or raising the saddle height.
To determine if your truss rod might need adjusting, check the relief (curvature of the neck). Ideally on a Strat (or similar guitar) many folks prefer an almost flat neck (for the lower action) with just a tiny bit of relief to prevent fret buzz.
To check the relief, you can sight down the neck to see if it curves and if it is concave or convex. Or even better, press down the low E string at the 1st fret (or put a capo on) and somewhere around the 17th fret and check so see how high the string is above the fret at the halfway point. If it's touching the fret at the halfway point it may be back-bowed. If this is the case you will want to loosen the truss rod by turning it counter clockwise to allow the string tension to put a slight bow in the neck so the strings don't touch the frets (and buzz). Always wait a few minutes after making any adjustments before making further adjustments. If you loosen the strings to make the adjustments - you must check the relief under full tension at standard tuning to determine how much the adjustment has affected the neck.
If there is too much relief (large gap in the center between string and fret) you may need to tighten the truss rod to counteract the string tension. To tighten the truss rod (and straighten the neck) turn it clockwise ("righty - tighty"). I like just a tiny bit of relief on an electric guitar, more on acoustic.
Here is a good article on adjusting the truss rod How to adjust a truss rod
After you adjust the truss rod, check the action on each string and adjust the saddle height as needed to eliminate any buzz. Finally, adjust the intonation as described in the article linked in David's answer. When adjusting the intonation, be sure your strings are well stretched or played in and be careful to only fret the note at the 12th fret enough to get a clear sound (not muted). Pressing too hard on the fret will cause the note to play sharp and your intonation will be off.
As long as you follow the advice above and in the linked articles, it is very unlikely that you could harm your guitar. Worst case, if your attempts at doing your own set up fail, you have not spent any of the money you have set aside for a replacement guitar.