Returning player

Hello guys

I am returning to the game after around 10 years or something, the last time I played I recall that perhaps the most rare and new dragons were the Gemstones, sun/moon/rainbow dragons.

What are the best strategies to get DC or to generaly be better besides paying

In case anyone ia curios on why after so long is because I used to play this on middle school with my dad and he recently passed away and I recalled the game, he continiue to play after I left and he had a great village after that he stopped but I want to return tu the game