https://classicdb.ch/?talent#sAxu0gotZVf0tbb
That’s what I would do. Put your first 13 points into Ret, getting SoC and Pursuit of Justice. Then go all holy, and finally finish out in Ret.
When I played Classic, I always ran with Blessing of Wisdom up, just to cut down on downtime. If you’re not running that, I would swap those 2 points to Divine Strength.
You can easily heal the first 40 levels without talents, so these holy points will keep you going. If you think you’ll run out of mana holy shocking, you can swap that points over to Sanctity Aura for more efficient leveling.
This is assuming a PvE server - I’d swap out a few talents if you were rolling PvP, such Unyielding Faith and Eye for an Eye.