I used to record with OBS, but at first it was kinda complicated and very laggy (but also because my pc isn't the best).
If you have Windows 10, you'll also have the Xbox app-thingy. You can find it by clicking on the Windows icon (bottom left) and look for it in the list of all apps. Once you've done that, press the Windows button (on your keyboard) + G and the app will automatically open a tiny menu with several options (including record ofc). If I'm not mistaking, you'll find your recordings in a folder within your standard Videos folder.
If this is too complicated (not because of you but because of me explaining it xd), you can always search on the internet for better tutorials on that ;)