Installing WordPress Locally on Mac w/ MAMP with one site already on comptr

I am already using wordpress for a site.
I need to simply find a theme or two and build some new sites.
I want to build them off line then upload.
I read the info about MAMP.
But, since there are no warnings, etc., I’m asking the question I need to ask that I don’t know in order to get information that may help.

Can I go through the entire process of downloading MAMP and then downloading the WordPress software without it messing up anything I’m already doing with the site that exists?
Thanks.