As requested, here are some places to look. Golden age comics are the best for this sort of silly stuff and many are public domain, so there are multiple places to look for them. Be warned, it is overwhelming. They churned out comics back then like they were gum wrappers.
https://digitalcomicmuseum.com/
https://www.pulpmagazines.org/old-comics/
https://www.comicweb.com/golden-age-comics.html
Feel like wading through the mess of the Internet Archive if you like: https://archive.org/details/comics
If you wish to brave the evil that is Reddit, there is: https://www.reddit.com/r/GoldenAgeComics/
If anyone has other resources, feel free to add them. Please no pirate sites, there's a lot of "read today's comics online for free" sites which would violate lemmy.world ToS.
Another good idea is to get an image compression app. I tried a couple online sites, Sqoosh and Image Resizer, but those were having trouble on mobile for me.
So I ended up just DLing an image compression app from the play store, and it works great. The one I got was "Photo Compressor". It has ads, but you can do multiple pictures at once to limit the ads.
FYI this one works great on Android, and is open source:
https://f-droid.org/packages/com.caydey.ffshare/
Not sure if it's on the play store or not, but you can download the apk directly from that page if it's not and you don't already have F-Droid installed
I usually just take screenshots. It's quick and easy and not massive in terms of images.
My screenshots are always too large, even after cropping.