Why exactly are you taking it in?
Was this machine under $200 purchased new? I'm asking because the tension tends to be not as good on these machines. My Bernina will hold correct tension no matter what I feed it, but lower-end machines sometimes require a lot of fiddling with tension and will not hold the tension adjustment over time and with different fabrics.
Also, a machine that was new a year ago basically does not require oiling. At most, it may appreciate a drop of oil in the bobbin race area. Some machines have a tiny felt insert (inside a hole) to take that drop of oil.
Tension adjustment starts with adjusting the upper tension knob. Test tension by doing a wide zigzag. Use different color thread in top and bobbin. An ideal balanced stitch will not show top color on the bottom or bottom color on the top. (If you get just a dot of each color, that's about as good as it gets on most machines.)
The bottom tension can be adjusted too, but that is trickier. I don't know how to do it with drop-in bobbins. With the more typical bobbins, you just have to read up on good procedures to follow to adjust the screw in the bobbin case.
The other thing a technician would do for routine maintenance is clean out any lint. This usually requires removing the needle plate (easy on most machines) and using a vacuum cleaner to suck out any lint. (Can tape a straw to a regular vac to do this at home.)