how to align sound with the video?

Hi guys, I've just downloaded the free version of Adobe rush to play with on my PC, and I already like it, however I have a little issue I can't solve: for some reason when I edit my videos I want to join and crop, the sound is deleyed with respect to the video which ruins the whole project. I saw a few videos on YouTube about the sound, but I don't think they're actually covering this issue. Can you help me with it? I'd love to purchase the full version, but will this issue remain? I'm not a technical person, Cheers