Im not very good with computer jargon and ive never made or managed a website before. Could someone please explain to me what an atom is and how this fits into making my website?

An atom is anything that shows up on your website. The most common atoms include text, menu and login. Each of these is its own section which make up your web pages. Atoms can either be used to view content or perform a function. Essentially atoms are the framework of your web pages and can be set to many different fuctions.