Yaku Cheat Sheet (from r/ffxiv)

Online Scoring Calculator http://mahjong.onevis.net/

Also this is a really helpful book https://dainachiba.github.io/RiichiBooks/

And I found this efficency trainer really helpful. https://euophrys.itch.io/mahjong-efficiency-trainer

Also found a scoring trainer. https://scoringtrainer.konbamwa.net/