If I'm going life cleric, I'm fully embracing support. Hill dwarf for +1 WIS, +2 CON and an extra HP per help just so I stay up to get others up. Plus heavy armor without need for STR. Start with Bless and cures, make sure I always have a Concentration buff/debuff/crowd control going. Make sure I have enough CON for Concentration checks (and HPs).
Not sure if WIS needs be #1 if I'm not attacking, but with WIS and CON as my only requirements why not. Maybe with point buy start with S 10 D 10 C 16 I 11 W 16 Ch 12. Really, W 16 (15+1) and CON 16 (14+2) are the only requirements.
With my relative load of defensiveness (good HPs and AC), make sure that I take some attacks. Spread out the damage so no one goes down. Especially in Tier 1 be open to ideas that that occupying a chokepoint and taking the Dodge action will be much more effective then tossing a cantrip for the chance at some minor damage.
AC 18 (chain mail + shield) at 1st level with just class given equipment, up to AC 20 when an afford to upgrade to plate. HP 9 per level (12 at 1st) between the 16 CON and the Hill Dwarf +1/level. In tier 1 (where most damage is still 21 or less so it's the base DC 10) there's only a 20% chance to fail a Concentration check even if damaged.
Don't neglect non-concentration spells. Sanctuary, Blindness/Deafness, Spiritual Weapon. Though Spiritual Weapon at times can compete with Healing Word if you need the range or want to take an action.