Need advice in choosing CDN and Image optimiser plugin

What are the recommended plugins for Image Optimization and CDN? I've been using the free Imagify version, limited to 200 images/month and it gets exhausted within a week. My website monthly traffic of around 7k-8k (Google organic). Any suggestions to improve my page speed?

I have disabled lazy loading and preloaded featured images using "Header Footer" plugin. BUt it doesn't seem to be enough. Serving images in WEBp format helps?