Bless? Nonono. You use your CD for +5/+10Your feats should be going towards resilient constitution. I would not take great weapon master too early. Divine favour is better than bless and -5/+10 at first. You can cast it with a bonus action. You could of course cast bless and use your extra attack immediately but it's usually not worth it in the beginning.
A 16 in Strength, a 14 or 16 in con and a 14 or 16 in wisdom is all you need for stats.
If you are a variant human or goliath that will be easy to get. Also as a dwarf. Variant human allows for resilient con or heavy armor mastery at level 1 to increase your chance to hold concebtration. Goliath can reduce damage once per short rest. Dwarf is golden with +2 Str and Con saving valuable generation points. Standard human is not too bad either actually.
The most optimized spread would probably be variant human with
15+1 str
8 dex
15+1 con
8 int
15+1 wis
8 charisma
Resilient constitution.
That would not be my personal favourite however.
I'd prefer
Goliath
14+2 str
8 dex
15+1 con
Int 8
Wis 15
Cha 10

Inversely I recommend leaving Resilient Con to level 8 at earliest, when your proficiency really starts to make an impact.