im looking for good lvl 10 gear what mobs drop the best?
can i find capes or helms in teir 1?

Well depending on the PQ and the places that the endless trial allows you to go to you can find gold set pieces.
Can you tell me what server you're on and what faction.

Helms and capes can be bought from renown merchants.

There are no cape, shoulders nor helm drops in tier1 anymore. All those pieces got replaced with level 12 gear, so nothing drops it now. Your only hope is to buy some of the old drops from auction house, and get ready to pay a lot for them. I am saying this only because I spent two days killing every mob that has chance to drop twinkie gear repeatedly and all I saw was level 12 gear.