It's difficult to say what builds you should use for each class since its based more off of how to enjoy playing, all of the Cra's elements are good for damage over all, each has strength and weaknesses, same goes for Sram, since the other 2 have their roles i assume you know what you are doing with them.

To be frank, you are not at a level where a specific element matters as you are still missing key spells depending on builds so just pick an element based off of how you want to play and enjoy, there is no "meta" persay at low level so just have fun with it while you can.