i cannot find out how to do files and folders

These tutorials are designed for the new to Mac user:

https://support.apple.com/explore/new-to-mac

Well, your post’s title mentions files and folders, yet the post’s body mentions pictures.

So clearly you already think the two are related. Please rethink this. You are very likely migrating to a Mac from Windows, where these two would be related.

In my strong opinion, the best way to organize pictures is using the Mac’s Photos application. Do not worry about where or how the pictures are stored, as the app will manage this for you.

You should obtain and study an excellent reference: “Switching to the Mac: The Missing Manual” by David Pogue. (I have no financial interest in this book.) I found the similar reference at the time I switched extremely valuable.