So as I was looking ways to compress images aside of online compressors, since the majority of them don't allow you to use entire folders, I runned into: https://www.xnview.com/en/xnconvert/
I found it pretty useful, since it allows you to just select a folder (like EventPictures) and it detects all the sub-folders and images. Then you select wich format you want it to convert, and it also provides an slider for quality (i.e.: you can reduce the image quality to, say, 80%, to reduce even more the file size). It also allows you to rename and give a secuential order to the images

Wich other batch conversion/compression tools you know/use?
Wich batch rename tool you use?

I use the tinypng photoshop plugin (because it's fast).
Shilo recently started using this https://www.guetzliconverter.net/
Some also recommend https://optimizilla.com/

For renaming I usually just shift+right click to open powershell and use
dir | rename-item -NewName {$_.name -replace "0_","2_"}to replace stuff in the current directory.  The replacement text supports regex, like "^0_" to replace only starting 0_'s.

Gimp also has a batch conversion plugin that works great.