Two different anti-virus programs installed at the same time is not a great idea, because the actions of one scanning, look like 'trouble' to the other one. You only need one anti-virus program, plus a firewall, (usually a separate program, but some are combined antivirus/firewall). On a new pc, the 'pc health advisor' isn't going to tell you anything worthwhile, in fact, might even show up false or not important information.
It's a given, in trial software, to throw in a few 'problems', to urge you to buy the full version. If you like the trial anti-virus program that was installed from new, you can upgrade, or extend the license, and it should be fine. But if you prefer a free program, be sure to uninstall the other one first. The makers of the program provide a special program to uninstall it properly, and it will be on their website. Or just Google; eg; 'Mcafee uninstall software', or 'Norton uninstall software', and you can then be sure the new anti-virus progam won't clash with the previous one.
A worthwhile program to install to keep a pc running well, is 'CCleaner', which you can download from;
https://www.techspot.com/downloads/132-ccleaner.html
Use the program as it installs, don't be tempted to tick all the extra boxes at the bottom of the list, it's all set up fine for most users.