Here are some priority heroes you should ascend first if you have 8/8 copies for them - You can use this to see the priority heroes you should put on the wishlist. This is a sorted priority list (Which means do them left to right if possible).
I would not get stars on anyone (carries or for engravings) until you have at least 8/8 copies of the priority heroes (The first group of heroes) - Max 2 spots on WL for stars, after priorities. Check in #classic-questions what heroes are best for starring, but generally you want heroes that unlock good bonus stats from e30/e60 with the stars, and will be engraved
I would keep scrolling GB until you have the priority ascended (The first group of heroes, the 4 GBs) - once you have 8/8 copies of the priority GBs, you can use the cards on lightbearers, but keep scrolling GB for fodder.