Change browser to Firefox as default browser.?

[user1h4zo5J6sl]

New to smart phone and new to S21 Ultra.

I want to change browser to Firefox as default browser. How do I do this?

I want to download Malwarebytes (I already have an account w/ Malwarebytes for my PC). How do this?

I'd like to be able to use the phone (not to make calls, but to download apps, etc. by using my Internet connected router's wi-fi. Can I do this, and how?

Thanks for reading and for any suggestions.

[user1h4zo5J6sl]

Thanks! I did that, and selected the only available option (free version). Now i am trying to figure out how to get my premium version (in the account on my PC) to cover the phone version, as well. I tried to do that from booth the phone and the PC without success.