Loud Fan Noise

My MacBook isn't even a year old when these things happen. It happens very randomly. Most of the time I do my school work and other things. Then the fans go off and the lag comes in. I'm not very smart about these things but I believe that this shouldn't happen on my MacBook which is almost new. I believe that I might have a malware but I don't know any free Malware programs for MacBooks.

[Edited by Moderator]

Thank you 🙏