I suffer from "severe" sleep apnea and have been on CPAP for 6 months with the full face mask. I did the at home test many years ago, but could not make it through the night because I kept getting tangled in the cords and wires. Finally, 7 months ago, I did another test and made it through the night and was immediately diagnosed.
My observations based on my journey so far:
1. Six months of wearing the mask and its still hard to get used to. I have a full face mask ResMed Air Touch F20. There are times where I wake up in the morning and find I have removed the mask in my sleep. I am a back and side to side sleeper, so it can take a while to get used to the tube that connects from the machine to the mask.
2. When you get started, you may discover there are certain settings in your machine you cannot adjust. For example, you may have to have your doctor or care provider adjust the air pressure. My initial setting was too strong.
3. The term DME is durable medical equipment - which is used a lot in discussions about your machine and accessories for the machine. You will find that the DME supply company will offer up re-ordering programs for supplies such as replacement tubes, filters, etc. Everyone has a different opinion, but I feel like its a bit of a racket to get you to spend more and more money. I have set reminders on my phone to regularly clean all of my equipment and change my filter, but have also ordered an extra tube and filters to change out ever so often as I am cleaning the original equipment. But again, everyone approaches this differently and some users are adamant on re-ordering and discarding their tubes every 2 or 3 months. I bring this up so that you can be aware that the costs add up. In my experience, I have found that replacement supplies are much cheaper on Amazon than from the DME supplier.
4. I have learned so much from other people's experiences on CPAP through the subreddit page:
r/cpap Some people love reddit and others hate it. On this particular subreddit I have found that when I experience something new or have an issue, there are lots of people with the same issues and sharing solutions.
Best of luck on your journey.