Hello! Sorry for the late answer!

From what I see it takes a good in time playing

Yes it does. You just need to have patience. :)

I would like you to give me some recommendation to get a better use of the game

In the beginning, I was attacking too much in the opponents face, try instead controlling the board. Then you have a bigger chance winning the game.

Here you can get help building a good deck:
https://hsreplay.net/decks/

There a lot of good hearthstone players on youtube. Watch their videos and you will learn a lot.

Try to complete all the daily quests, you need as many gold coins as possible to buy card packs! :)

Craft only the cards you really really need.