pixel_player652839380 As you progress through the levels it will get harder and harder to keep up, sometimes seemingly impossible. What you are learning now is very commonly discovered in the 100 to 200 level, the art or the mechanics that form the engine room of this game.
Players use different strategies and rightfully differ in opinions on this sometimes. If your game plan is to keep TH and other buildings up to date, then the advice above regarding avoiding XP is paramount. For most part it cannot be avoided, but the parts you can avoid, for example doubling rewards if you watch an advert should become less attractive if it includes doubling XP. It is these types of extra XP earners that will tip you over the edge. The other thing you sometimes need is time. Slow playing and long commodity trips can help you catch up (huge caveats on this as there are other factors that kick in too).
Keep in touch on the forum and soak up some of the expert advice here by all the contributors, because as you progress through Lvl 200.. 300..400 etc, you will enjoy the game, yet be faced with more and more pressures to keep up. Perhaps put simply, the game does get harder.
Lastly, check out this link HERE It is a good list of tips.