A lot of people worry that compressing a photo means ruining its quality. In practice, if you get the order and method right, you can shrink a photo a lot while the result looks nearly identical to the eye.
The biggest tip is "don't pick a quality number — pick a target file size." Guessing whether quality should be 70 or 85 gives inconsistent results from photo to photo. Instead, entering a target size like "under 200KB" automatically finds the best quality that fits inside that size. Different photos need different amounts of data (a flat-color background compresses easily, a busy pattern needs more), so the same quality number produces very different file sizes depending on the image.
The second tip is resizing first. Modern phone cameras shoot at well over 4000px, but for social media or a blog, around 1920px looks identical on screen. If you keep the original resolution and only lower quality to hit a target size, you have to drop quality much further, and the blur becomes noticeable. Resizing down to what you actually need first, then hitting your target size, gives a cleaner result.
Finally, pick the right format for the job. Photos with complex colors do better as JPG or WebP; images with text or simple graphics stay sharper as PNG.
If you want to resize first, use Resize Image to set the longest side to around 1920px, then use Compress Image to enter your target size.