How to Optimize an Image-Heavy Website for Faster Loading and Better User Experience?

Hello everyone! I’m currently running a website dedicated to high-resolution images for users. However, due to the large number of images and their high resolution, the site’s loading speed is quite slow, impacting user experience, especially on mobile devices. I’m looking for some tips on how to optimize my website while maintaining good image quality.
Here are some questions I’m particularly interested in:

1. What’s the best image format to use?
   There are many formats like JPEG, PNG, WebP, etc. I’ve heard that WebP can significantly reduce file size without much quality loss, but I’m not sure if it’s compatible across all browsers.
2. What should be the ideal size and resolution for images?
   If I set a smaller image size but display it larger using CSS, could this negatively affect performance? Is there a way to automatically adjust image size according to the user’s device?
3. Which tools are best for compressing images?
   Currently, I compress images using Photoshop before uploading, but it still doesn’t seem fully optimized. Does anyone recommend a tool that effectively compresses images without losing too much quality?
4. Is lazy loading effective?
   I’ve heard about this technique to load images only as the user scrolls to their position, which should reduce initial load time. Does lazy loading significantly improve page speed, and does it affect SEO?
5. Is a CDN necessary for image-heavy websites?
   Does using a Content Delivery Network (CDN) for storing and serving images really improve loading speed? Are there any budget-friendly CDN providers that would work well?
6. Which WordPress plugins are effective for image optimization?
   Since my site is on WordPress, are there any plugins that you’ve used and found effective in optimizing images?
7. What should I keep in mind for SEO when optimizing images?
   I want the website to not only load faster but also be search engine-friendly. Any advice on factors like alt tags, file names, and image sizes for better SEO?

I would really appreciate any experiences or recommendations you could share! Thanks a lot!
My website: imagenes de buenas noches nuevas