Flight Prices And Weird Routes

I've been looking at flights for quite some time now to go to Canada and America. Well I've noticed that it works out cheaper if I go to Canada then America. I'm not sure why. Also to get from the UK to America without going to Canada first, the journeys seem to be taking some very strange routes. For example if I want to leave from Gatwick in London, I would have to change planes at Munic or Frankfert or however you spell it, or if I leave from Manchester or Birmingham I would have to change somewhere equally as weird like Brussels Madrid or Zuric. I know I'm going to the south or southwest of America, but to me it still makes little to no sense to fly east in order to go back west. One thing I thought I could do is perhaps look for flights to some of the eastern states then go from there if I wanted to avoid Canada altogether. But then I want to go to Canada too, seeing as that isn't a part of the world I've visited. Speaking of weird travel routes, I'm going to Nan and Grandad's in a week's time, but national express coaches don't seem to go that way. It looks like I'll have to book trains after all because I really don't feel like going all the way to London to go back again. I have got the train pal app on the stupidphone though, which can make the tickets cheaper than using something like the train line. Apparently the app splits tickets already, so it saves me a job. In terms of flying, I also want to see what low-cost/budget airlines are around and see if those are any cheaper for getting to America than the ones that I assume pay to be on expedia. I don't have any loyalty or reward things, because I don't fly often enough and don't intend to.