Hello. I'm not a qualified professional teacher but I've searched for it and found the answers which I can understand as a native speaker so I'll write them down.
*回:
You can use 回 with 0, 第, 全.
ex) 第1回→OK 第1度→NG
0回→OK 0度→NG ( you can say 0度 if you are talking about temperature or angle but not when counting numbers)
You can use 回 when...
・you can see the beginning and end of it clearly. ex) episodes of stories, number of classes or events
・you can predict next time regularly. ex) 今回( this time )→ OK 次回 ( next time ) →OK
*度:
You can use it when...
you can see the beginning and end of it but not clearly.( it can be changed by how much one is putting the value on )
ex) 一度にいろいろ話す( talk about several things all at once) 、この度はありがとうございました( thank you for this time * today )、今度 ( at some point which would come as next time )→OK 次度→NG
Thank you for leaning Japanese! I hope it can help you a bit.
べんきょう、がんばってください!