Hey there, arpan162.
Welcome to the Apple Support Communities! Thanks for your post about not being able to get iCloud Photos up and going once you turned the feature on. We'd be glad to see how we can help.
Uploading your Photos to iCloud initially might take a pretty long time depending on the size of your library. This could even take a few days depending on a few factors. Also, for the fastest transfer rate, make sure that you're connected to both the charging adapter and a strong Wi-Fi connection. Check out a few other tips in Get help with iCloud Photos.
Hopefully that helps. If not, let us know what's happening.
Thanks