Crank Compatibility for my Orbea Hydro 2012 I have received as a gift a set of SRAM bb30 cranks. I would like to know if they fit my 1012 Orbea Hydro and if can I use SRAM Alloy GXP Bottom Bracket to fit it all together.
You cannot use a GXP bottom bracket to "fit it all together".

BB30 cranks do not fit in a GXP bottom bracket. A GXP crank can be made to fit a BB30 bottom bracket with an adapter, like one from Praxis.

If your Orbea is a GXP standard (24mm) the cranks are no good to you as they will not fit.  If it's a BB30 they will work without the need for any type of GXP bottom bracket.