Are the precise resolutions absolutely critical, or is it just that everything that's the same size needs to be the same physical size as everything that's the same size?
If the latter, just send everything to a photo printer, and pick a size of photo roughly the size you want. They'll blow everything up so it fills the size you selected in a way that doesn't look that shit. They use AI to do it, so don't expect it to look as good as if you resized it yourself, and expect them to crop off one or more margins to get the pictures to fit.
If your source images are shit, it will still look shit. Do you not own a phone or something? Look at the images you're sending on your phone, and if they look shit on a phone, they will look shit in print.
You can achieve exact sizes from photo printers by printing a test sheet then crafting images based on how it comes out (>>525581
), but that's probably beyond your capabilities.
If you don't mind mail order and 2-3 day lead times, you can get $0.05 a print for big orders. Plus if your images are shit they'll just print them anyway.