Learn to do it by hand with a file.
I started cutting cordwood for the home and to sell when I was 13; wood was $40 a cord back then. The saw was my my Father's super XL. I learned just using a file without a guide. It did take a while to get good at it.
Things I learned beside the filing: 1) wear gloves to avoid skinning your knuckles, 2) It's easier with the saw clamped in a bench vise, 3) make sure chain is tensioned properly, 4) every few sharpenings take off the bar, clean the grove, dress the rails with a bastard file by draw filing, flip the bar when re-installing., 4) check the rakers every few sharpenings
Later I got a Oregon file holder which helped me keep the file at proper depth when filing, but I got by without one for years. I'd get one for new filers. Also get a depth gauge for the rakers.
Read up on how a chain cuts and how to sharpen before you start learning. Have a sharpie to mark the chain where you start on cutters, inspect the cutters that you have them sharp. Only file a cutter enough to get them sharp, the feel of the file stroke will let you know.
You also will appreciate not turfing the chain or hitting rocks/metal if you sharpen your own, and be able to dress the chain in the woods if you do.