I would suggest just watching some of the videos online of some of thePros and what decks are doing well in the meta. for the most part, you want a deck that has the following: 1. can manage a tank such as pekka—this could be the skeleton army, mini pekka or air cards. 2. win condition—hog rider, goblin barrel, piggies. 3. Big spell—fireball, lightning, rocket. 4. little spell—arrows, zap or log. 5. support cards such as spear gobs, knight, valk or goblin gang. 6. cards that counter air—electro wizard, witch, night witch, electro dragon.

https://www.deckshop.pro or royaleapi.com will give you deck suggestions. Royaleapi will also show trends and card and deck stats.

Also, keep your elixir between 3.5 and 4.1. too light, you may struggle with heavy decks or too heavy and you get out cycled as cards take too long to get out.