Please help me optimize my arcana cleric

I’ve chosen to play a variant human arcana cleric in the Greyhawk setting. He follows the god Celestian.

Here’s my basics at level 1:

8/14/14/12/16/10

Feat: magic initiate druid (shillelagh)

Question 1: what other druid cantrip and what first level druid spell help this character the most?

Question 2: I can’t decide between booming blade or green flame blade. I’ve read that booming blade is generally a better choice, but I’m not sure I understand why. Also, the arcana clerics level 8 ability favors green flame blade. Or should I just choose both?

I'd get both for your two wizard cantrips but Booming Blade is definitely the go to just because it isn't that common to have two enemies within 5 feet of eachother.

For your other druid cantrip I'd go for either Thunderclap for an AOE option or Thorn Whip for a pull attack to position enemies. For level 1 I'd pick between Faerie Fire for the group advantage or Absorb Elements for a nice defensive option that will come in handy all game and also amp up your melee cantrip.

For the Wizard Cantrips choose both Greenflameblade and Boombing Blade because the other Wizard cantrips aren't as important and you want to have different damage types and options available. For level 1 druid spell pick Absorb Elements, any other choice would be the wrong choice. For the other Druid Cantrip you should definitely pick Thorn Whip because when you use Spirit Guardians you can pull creatures into your spirit guardians to deal even more damage.

Also you stat distribution should be this:
Str 8
Dex 14
Con 15(+1 Variant Human) (reason for this is that it is better to have 16 con instead of 14 con so you don't go down like a ton of bricks)
Int 8
Wis 15 (+1 Variant Human)
Cha 10 ( or you could make this 8 and go with 10 Strength depending on your Cha checks and whether or not you calculate carrying capacity)

Thank you all. This character has been submitted so with me luck.

Here’s what I went with:

Variant human
Arcana cleric 1
Magic initiate (druid) feat

8/14/14/12/16/10

Cantrips:

Shillelagh
Thorn whip (I figure I can drag enemies into *spirit guardians* at a higher level)
Booming blade
Chill touch
Guidance
Light
Sacred flame

I also chose absorb elements as my level 1 druid spell.