Being a good hearthstone player takes a lot of work. Here are some tips:
1. Go to
https://tempostorm.com/hearthstone/meta-snapshot/better-late-than-never. Pick one and only one of the top decks.
2. Get the cards to build that deck. This step might take a while but dust every single other card you have. You will not need them again.
3. Now you need to watch a lot of streams. What you are looking for is when a top streamer tells you to change the deck ever so slightly by substituting in or out exactly one card. Once you get the ok, follow their lead.
4. Play this deck repeatedly.
5. If you have problems playing against a particular deck, do not be tempted to make changes to your own deck. This is an awful idea and now how hearthstone is played. Instead go on message boards and complain about that deck.
6. After one month, go back to 1.
That should help you get started, and finished with Hearthstone constructed play.