(almost copy paste from another post I made today)
Welcome to the forums, the best part of the game!
Little intro to the forums:
There are new decks posted every day
HERE, where the feedback uses to be awesomely useful for deckbuilding.
As every new player, I will lead you to the
Tutorial Section, where you can find many useful (and not so long) guides, like "9 tips for deck building" and "5 things every Elements player should know". As you started today, don't miss Xeno's "1.29 Newbie Tutorial: Becoming Rich the Fun Way". Those are the 3 links I recommend most of the Tutorial section.
As you get into the game, its mechanics and strategies, you will LOVE to participate in the
Weekly PVP Tournaments! They are fun as hell and the reward for the 1st and 2nd places are a Nymph! (or a Mark, but Nymphs are useful, ultra rare and extremely powerful)
As a last comment and self promoting myself a bit, you can look at MANY deck strategies and synergies in the link to the tutorial of the bottom of my posts, where you can also find a guide to my favourite deck style called OTK (see link for more info)
Again, welcome and don't doubt about entering to the Community Chat (at the upper right corner of the home page) to have fun, talk with many new and experienced players and ask anything you need.