Make sure you are throwing confetti chips and not saw dust. If you're not throwing chips, the chain need sharpening.
Depending on the cutter type and the wood type, you may need to sharpen often. Keep an eye on the chips and touch up the chain whenever you're not throwing confetti chips.
Only adjust chain tension with a cold chain and expect it to loosen a little when it warms up. If you adjust a warm chain, it will be too tight once it cools off, and it can actually bend the saw's crankshaft in extreme cases. Properly adjusted for tension, you should be able to grab the chain and push it around the bar with a flick of the wrist, and it will move a little on its own.
Modern saws do not oil a lot (even the pro models). But you should see the oil level going down over time. You can run the saw with the bar removed to make sure oil is dribbling out the oiler hole. Then run the saw with bar but no chain and you should see oil dribbling into the bar slot through the oiler hole.
Look at the cutters, are they showing signs of overheating, like bluing go the metal? If so, it's either a dull chain or a poorly oiled chain, or both.
As mentioned, it's a relatively small saw. I have a 40cc saw, and it will cut 16" hardwood, but it will work hard and it takes a while. To me, a 40cc saw is for limbing.