I'm playing a Peace domain cleric in a new campaign.

Not decided about what race to play and for once don't really have any strong preferences.

Does anyone have any recommendations or favourites? 

I tend to go High Elf as the bonus cantrip can always be useful.

Are you using Tasha's cutomized origins? If not I would go for a race that boosts wisdom.

If you are using customised origin you can pretty much choose any race for roleplay reasons but I would ask yourself/the DM the following questions  to help you decide?

• What races are allowed bythe DM?
• Will any races result in difficulties with social encounters (for example will most of the people you encounter be suspicious or even hostile towards monsterous races)?
• Do you want flight? (Winged tiefling allows you to wear medium armour)
• Do you need darkvision? (you might want to consider how many others in the party have this and whether they will want to explore dungeons without a light)
• Are their any feats you particularly want (it is usually optimal to take ASIs until your wisdom is 20 meaning you wouldn't otherwise get a feat until level 8 or 12)
• Do you want to be decent at thinks like Religion/Arcana or face skills? If so you can be a bit MAD needing decent Con and Dex and Int/Cha as well as Wisdom, one solution to this is to pick tortle for a decent AC while dumping Dex.
• Are there any specific spels you would like access to?

Do you want to play as a hippy "peace man!" type, an enforcer of peace, a negotiator or something else?
I'd consider
Fairy, Firbolg or tortle for the theme
Leonin or yuan-ti for the conflict
Also like Loxodon as the lumbering peace envoy with that trunk to pull people apart.
Firbolg or Loxodon for the stats
Varient Human for the feat.