You can try some free Linux antivirus software programs like ClamAV but realistically, as long as you mainly install software through your distro’s package management software or graphical app store, you’re probably fine.

Although not all open-source software is safe, it’s a hundred times less likely to be malicious for the sole reason that it’s out in the open for someone to verify, and they’d get busted immediately if they tried something untoward.