Then go for any species you like, and pick Magic Initiate at lvl 4.
If you start at lvl 3 you just have to handle one level of your attacks doing a couple damages less and being a bit less accurate than a typical Monk. And even them that's only when you don't use the Astral Self's subclass abilities.
All in all nothing that's a big problem.
Or you can also just go for an Astral Self Monk without Magic Initiate and increase your WIS at lvl 4, meaning you do a bit less damage and have a bit less accuracy when you're not using the ability, but more of both when you are. Which works fine.
Or you can take Astral Self Monk and go for one of the species that gives you a WIS-based damaging option, that way you don't need to worry about your non-boosted-by-class-ability attacks at all.
Or you can take any build and use it for the "elderly Monk" idea.
Does your group use the Tasha's or Mordenkainen Presents: Monsters of the Multiverse options?