Well this game is pay to win, or spend a stupid amount of your life grinding out matches to get to a fair rank. I built a fairly cheap rogue deck which while isn't effective, it is fun. Got me to 15 which felt like easy mode, at 15 I feel like I hit a brick wall.

I am not saying that if the opponent has a massive epic, and I lost because of it. It just means if both players play their best in a given situation the guy with the more expensive deck will get ahead little by little bit by bit till they win or make a huge mistake.

Personally the most fun you can have I think is in arena where everyone is on more or less equal footing and you get to play around with all the crazy cards and skill feels like a much bigger decider. It is hard being new and trying to draft all these unknown cards but you will quickly learn.

I used to go 1-3 when I started(only about a week ago) but lately I have been hitting 5-9 after I started prioritizing my 2-3 drops and keeping a close eye for possible synergy as well as the mana curve. Watch trump and look up arena value to get an idea. But remember pick cards based on what you already have and ask yourself, if this was the only card I could play would it be good?

Other tips I can give you is learn the secrets which people play. When I started I had no clue what secrets did and how to play around them so I just ignored them; but after a few mirrored imaged 8 drops that lost me the game I figured I should figure out how they work. Don't forget flame-strike turn 7 and don't assume they don't have more then 2, last night I played around a mages flame strike and assumed that he could not possibly have 4 flame strikes so after the third I went all in and bam came another flame strike. Basically don't play anything you don't absolutely have to.

Good luck!