On your computer, please do not install more than one antivirus. You’re certainly welcome to use any antivirus you like: Bitdefender, Avast, McAfee, Norton, etc. But only one. If you want to change antiviruses, uninstall your current AV before bringing in the new one.
Why? The reasons can get complicated, but I’ll keep it brief: Two antiviruses can fight with each other and your computer will suffer the fallout. If you run more than one antivirus, your computer may bog down, kick up strange errors, or have problems loading websites.
So whichever antivirus you like, stick with just that one, and don’t pile on any others.
One exception: Microsoft Defender Antivirus (built-in to Windows and found under the white shield icon) is smart, and will turn itself off automatically if you install any other antivirus. And it should turn itself back on if you uninstall all other antiviruses.