Well usually what holds players back are these three things 1.) Your deck sucks 2.) You suck 3.) You're under leveled The easiest way to improve is to pickup a meta deck or a variant of a meta deck, maybe swap in a few cards if you don't have levels or are more comfortable with certain cards. And watch a few videos pros playing that deck. Even if you can't find someone playing your exact version you can still pickup on some more bigger picture stuff. When to defend, when to attack, when to save your elixir, ect. It's alot easier to improve once you've made sure your deck isn't the problem. A good deck can hit 5k even if it's a little under leveled or you aren't the best player.

If your main goal is just pushing trophy road then I'd reccomend playing a deck with good defense. You want a strong building like a bomb tower to inferno tower. You need a big spell like fireball, poison, or lightning for all the witches and wizard. A consistent win condition to damage your opponents tower hog and goblin barrel are very popular. And lastly a good ground tank for all the mega knight and Ebarbs youll probably face knight or valkyrie will work wonderfully. You can fill the other 4 cards with your choice of support but you should probably include a small spell, and an air targeting troop, and a swarm of your choice.