No problem.
In traditional manga, the lineart is the important thing, and tones are just like the icing on the cake. Some people choose to go all-out with their toning because that is their vision, but I try to use a little tones as possible to save time. I've looked at some of your pages and they look pretty great in black and white!
For backgrounds, I suppose you may begin by practicing the one, two, and three-point perspectives. There are tutorials everywhere on deviantART -- you can try doing a search: one-point perspective, and so on.