Windows 10 with Avast Free

I got a newer HP 15 sleekbook laptop. I redone it and installed windows 10 upgraded from 8. Looks like 10 has built in antivirus. It says if you install a antivirus it will disable the built in one. Should I install Avast Free or stick with the one built in? I never had windows 10 before. I also have Malwarebytes Free I run and update on my own.

Actually I have Avast Internet Security I can put on it. I will be deleting it off my old laptop. I just renewed for 2yrs for 3 machines. If I put this on it does the firewalls take care of themselves or does the windows firewall need to be disabled?

Everything should be done automatically.

So you think its a good idea and better protection for me to do the Internet Security?

Yes