Windows Defender is free and does a pretty good job catching most things. I would sprinkle Malwarebytes scans in periodically (maybe once a month?) in case you get any spyware or adware Windows Defender doesn't catch.
Since this is a laptop, I imagine you will be connecting to WiFi hotspots that are public and can be used by anyone. Do yourself a favor and invest in a VPN. Don't use a free one, use something like Private Internet Access or NordVPN. A VPN allows for an encrypted connection between your computer and its destination, protecting your data such as passwords, credit card numbers, even your emails so no one can snoop on your activity in public.
Finally, get a password manager. A password manager not only stores all of your passwords, but can automatically fill them in for you on websites so you can use complex, secure passwords like KjLd~SA99021jvlf! without worrying about remembering them (I know I couldn't!).
At the end of the day, you are going to have to end up paying for protection for your laptop, but it's the same as investing in a home security system with monthly monitoring fees, or cable. With so much of our data being stored electronically, it is on us to make sure we protect our personal information as best we can.