Setting Proper Permissions?

I am needing to re-setup proper permissions on my server, though since I’m a n00b at setting permissions, I need a bit of guidance as to what to set, (i.e. 557, 577 etc.) so that I can be secure, but still able to download certain files from folders on my server.

Any guidance is greatly appreciated, my site is https://www.pesosforpenguins.com

Thanks!