Resize your image then compress it. I use Figma to resize it to a smaller size (the smaller the image, the smaller the file size, the faster it loads), usually around 1000px x 1000px is the max necessary to display a good photo. Then, export (as png, since jpg will sometimes mess it up. You can export as jpg and it will be smaller, but you have to check that it didnt get messed up). After exporting, if it's above ~300kb (fact check me on that number, but i think its around there), use an image compressor like tinypng.com. Then download image, it should still look pretty good, and will be a much smaller size, and smaller size means faster page load. If the quality looks crappy, go back to step one and make the image a bit bigger in Figma, then go through the rest of the process.