Stuck on Asus boot logo after flash Lineage OS
If you are flashing a stock ROM for the first time, it takes a considerable amount of time to boot up. You could:


Try waiting a little longer(10-15 minutes)
Flash the ROM only without the GAPPS and boot 
Try another Custom ROM


If it boots up up without flashing GAPPS, then you  should probably use a lighter version of it, either 

pico or nano