Do i need a antivirus app for my new macbook?

You do not, instead read: Effective defenses against malware and ot… - Apple Community

I have never used an anti-virus app on any of my Macs, starting with a MacPlus in 1986.

I've only made sure I got the most recent Security etc. updates from Apple, and have never had any problems that could be attributed to malware.

The worst I've experienced is web sites that hijack the browser, and a simple Force Quit or reboot sorts it out.

You’re quite welcome.

I have a MacPro desktop now and my friends at Apple told me to put a Malwarebytes app on my computer which I did and its on my Apple dock now and once a week I click on it to see if I have a malware or not? When I put it on my Apple dock it was free at that time. A year ago, I went to Utube to see what was happening and reading what president was saying to the public and I had a feeling to use my malwarebytes and I was correct it had a malware that someone had planted on uTube on president Trump video. I went to the Apple app store to see what was available and found a few apps and it is not free anymore for your iPhone too.