In this day and age, you can do this for FREE and on the side, whenever you have time!

There are tons of very well-done professional level video courses on Youtube.

There are more organized courses that only ask you for money for the "extras", like some tests and a certificate, but the main parts, texts and videos, are free.

You could start with a really good teaching professor (Eric Lander, MIT) and his course: https://www.edx.org/learn/biology/massachusetts-institute-of... (the "Audit" track is free, ignore the prices; also ignore the "expires" - this course restarts every few months and has been available in new versions for many years now)

It's very engaging!

There's similar courses for everything in the life sciences, there on edX, on Youtube, many other places.

I feel the true Internet is soooo underutilized by most people! Forget news sites, opinion blogs, or social media. Knowledge is there for the taking, free. Only the organized stuff, where you end up with a certificate costs money, but they usually still provide the actual content for free.