Got my first XP just now as two piks who had been already journeying for their decor before the update returned. I got 200xp for each of them fetching decor, and 20XP for releasing one. When I'm able to level one I'll try to record that number as well.
Edit: Sorry, just realized it's not levelling but pulling them from the seed pots that gives XP — seems to be 30 but I may have lost track.