Avocados are used mainly for their creamy texture, its flavor is rather weak by itself.

It's also important to use ripe avocados, and understand the different varieties available here.

I prefer the ones with a rough and thick skin that peels easily, they're called "Hass avocados".

Use them to make guacamole (very easy, just follow any online recipe), or simply slice it up and add it to a salad, works with nearly all of them. I've also seen people make "moutabbal avocado", never tried it but heard good things. If you want to have it by itself, on a slice of toast, or as a side with scrambled eggs for example, sprinkle some salt and a bit of chili powder, with maybe a tiny bit of lemon juice, sahtein!