Just remember, the beginning is the slow part of the series. This series has tons of mysteries piled onto it.
Think of the ones we can think about from just the first episode:
-How many youmas are in the world hidden as humans, where do they come from?
-How exactly are the Claymores made? How does their organization work?
-Why are all the Claymores female?
-Is Raki completely worthless?
-Where do the other Claymores in the OP come into this series with Clare?
These are just some of the few. I hope that episode two will inspire even more questions like these.