Are u using a bucket or a carboy? If a glass carboy u will see a thick head on top of ur wort called a krasen.(it will be in a bucket too u just can see it without removing the top) in initial fermention your airlock should be going crazy. As for getting more yeast my closest homebrew shop is an hour and a half away I would wait it out before driving to get more(granted I keep extra on hand). Next order buy a couple of extra packs of yeast for just in case reasons. Even though this may not be the most popular opinion I use to just sprinkle my yeast on top of my wort. There was a really cool article in brew your own that talked about sprinkling compared to re-hydrating u should check it out.Chopps