Lining up the columns??

I’m new to css. And to WordPress. I had no trouble installing the program and with a bit of fiddling–and some nosing around css references linked here–managed to get my blog to roughly approximate the design of my website.

Here’s the URL of my blog: https://www.gymshoesmusic.us/Amp/
Not a perfect match of the website, but close. ??

The problem is with the columns. I have left and right nav columns in addition to the center where the entries go. The problem is that all the individually columns stop when they run out of text, so all three columns are an uneven length. (Scroll down the pages and you’ll see.) Since a lot of my entries are long, I just padded the hell out of the left and right columns to make them go down the page, but this isn’t a satisfactory solution because each page will be a different length.

Also, something weird is happening with the center and right (menu) columns. When the right column ends, then the center column spreads out all the way to the right. It doesn’t do this on the left. Of course, it wouldn’t be a problem if all the columns were the same length down the page. ??

I know this is probably something simple, but I’m going mad fiddling with it. How do I make all the columns even up?

Thanks!

Gymshoes