Hi there. I've been playing this game since 2014. Best tips I can give you are:
1. Play standard, they implemented it precisely for new players to have a chance.
2. Do NOT use your gold to buy packs. The rewards from the arena are much more worth it and even if you suck at the beginning don't worry. Many top-class players still do 0-3 runs. You can download the Hearthstone Arena Companion from
here and it helps big time.
3. If you get a golden card AND you already have it 2 times as not-golden - disenchant it, they give more dust, but I wouldn't advise to disenchant a golden card if it's your only one. You never know how the meta will turn around.
4. An exception for point 3 are the legendaries. When I was still new to the game I made the mistake to disenchant some legendary minions and although that gave me a significant dust boost I later ended up crafting some of these same legendaries because I really needed them.
5. Pick one or two classes and focus on making a tier 1 deck with them, rather than trying to build competitive decks with all classes.
Hearthpwn is a great site to keep up with the meta and know what to craft, what to build and how to play.
6. Try to get as less cards as possible from Whispers of the Old Gods and Mean Streets of Gadgetzan and don't attempt to complete One Night in Karazhan. These sets will very soon be moved to wild format.
7. At the end of each month you'll get some rewards depending on your rank so Ranked > Casual. Also never skip a brawl. One win gives you a classic pack.
8. Once a day you can re-roll one of your daily quests. So if you log in and see that the quest gives you 40 gold you can swap it and hope for bigger prize. If the reward is anything but 40 gold, however, you best leave it be.
Hope that helps :)
