Help me (CM 12 and Gapps) topic

Hi
i have installed CM12 nightlies on GT-i9505. it's installed successfully.:D it's very cool rom
but when i try to flash (gapps mini modular)it abort from install and error [status1]. in the gapps for lollipop say that your CWM version not support this gapps version flashing (6.0.4.7).
now, i tried to flash twrp latest version on device in downloading mode but i have error in this.
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Get PIT for mapping..
<ID:0/003> There is no PIT partition.
<OSM> All threads completed. (succeed 0 / failed 1)
and not happening.
Q2:
how can i root my device in android 5.0.2?
please help me guys!