I've been having problems since my neighbors raised their garden I think it's algae and a small green weed all over could some one give me any help

Close up photos would help.
Weeds you don't want are best manually pulled.

Take your umbrella.

In most of the US, it's illegal to artificially raise the level of your property (e.g. with fill dirt) or alter it (e.g. with a ditch/swale) such that it sheds water onto another property. I'm not sure how that plays in Glasgow, but a little research will tell you whether or not you have enough leverage to force an equitable resolution.

Al