Just started playing and my cards sucks. basic deck can't get me far. i can only open one pack every two day just base on quest. not sure if i should do arena instead
You'd be surprised what people can do with basic deck, don't be discouraged. Some of the more pro hearthstone players are doing ladder F2P without spending money and building their deck only through gold obtained online. It's also partly down to which cards you pick based on what cards you have and which hero.
Arena can be tough if you aren't familiar with the cards yet as you'll see alot of new cards if you just started playing and do arena. Some you may think are useless but after playing awhile, you realize how you can use them, so it's best you play against AI for abit to build up basic cards for the various heroes and same time see the different cards that are available for play in a game.