i'd recommend reading the readme within the .zip. kivan and quarn are excellent about including installation instructions with the UxPs. 'tis just a .txt document, but a fantastic starting place.

If you do start installing more stuff on top of the unofficial patch, you'll probably want to use some form of mod manager. Nexus Mod Manager is probably better for people new to it, with Wyre Bash being preferred for more advanced users and complicated mods.

If you just plan on installing the unofficial patch though, generally just dragging the relevant files into your data directory and ticking the .esp in the launcher is fine. Make sure to read the readme for everything you install, though.