Steps to make a macro applicable to any cell that I choose

Hi
I have a few questions before I create a simple macro, wondering if anyone can help?

I know there is a tab excel recommends you add to the excel ribbon in order to deal with macros, wh tis it called? I forgot! And then obv, what steps do you need to actually get it there i.e. add the tab to the ribbon?


And one more, sorry, after I have made my macro, if I want ot to be applicable to any cell that I chose, what is it that i must do? I.e. what do I have to remember to include in the process of making it?

Cheers, I know these are pretty basic questions, but I am a bit lost!