After Effects does a lot on its own, but many editors add plugins for effects it cannot do as well. Several presets in the shop are built on these plugins, and won't work without them.

Start without any

The Starter Pack and the free Colour LUT use only built-in effects. If you are just starting out, begin there and buy plugins only once you know you need them.

The four plugins, and what uses them

Try before you buy

All four have free trials. Install a trial, try the matching preset on your own footage, and only buy the plugin if you will keep using it.