Meta Tag Manager

Hi

I am new to WordPress and therefore I am struggling with using it. I don’t understand how best to go about using SEO’s and Meta Tags, I noticed that you can either do this page by page or by istalling Meta Tag Manager, is this correct? I have installed Meta Tag Manager and I don’t understand what I am to wirte in “meta name” and “content”, or how many tags I can have for the website.

Please could someone kindly assist me as I have looked everywhere, WordPress forums, YouTube, and various articles but haven’t succeeded.

Thank you.