Why is my new computer having so many problems?

I bought a brand new computer (a Lenovo, maybe a 2016 if not 2017) and I'm already having problems with it, I keep getting messages saying the internet isn't responding or that certificates for sites are not valid (tons if I'm playing games and don't see them) and a few other problems

I have MacAfee on here as it was pre programed (I didn't know it was on already) as well as malware antybytes for security

I think it's a windows problem. You do just setup the windows 10