Right click on the source database that you want to generate the scripts for. Go to Tasks. Go to Generate Scripts. And then select the database that you want to generate them for (just pick the one you're interested in). Hit Next. Then select the different objects you want to generate. If you just want the tables, just pick tables.If you're concerned about the procs/functions/etc. Click those as well. Click Next. Then it will go through each of the categories that you clicked and you select the items that you want to be generated.
After you're done hit finish. I generally put my export out to a file or to a sql window (not to the clipboard unless i'm doing something that i don't normally do).
But then you'll have the schema of what you had in database A
