Hey i really wanted you to buy a betta! And i know you are new to the fish. I gave you those links but i am aftraid it might confuse you. If it confusing you really don't have to use the filter and can just simply do regular water changes. I do it for long time and many other people on the forum do the same. So if you need help let me know and i will instruct you about water changes.
If you decide to keep the filter , and will baffle it make sure you swish/rinse it weekly in the dechlorinated or tank water. And vacuum the gravel weekly along with 50% weekly water changes.