Avast - Antivirus (Just use antivirus)
Comodo - Firewall (Just use firewall of them)
Malware bytes - anti malware (stand alone, you can run it periodically)
Adblock - in chrome, firefox (newer ie is very good)
If you are little familiar on technical side, then get Pi Zero W ($10), set it as Pi hole. But above list should be good enough for 90% of people.
Last 10 years, i lived with the free anti sw without any issues.
If you want to pay, avast has premium feature.
I used Norton, Bit Defender, Avira, Mc Cafe, Avg. On paid versions i liked Bit defender. But I am using Avast last 5 years with no issues and its free version. If you just avoid shabby websites, less porn you should be ok.