How about:

jeSlaH ghojwI'pu'

learners can participate

That's the cleanest translation I can come up with, and while its not exact it would serve most purposes.  If you really want to make it conditional on volition, it would be at least somewhat less awkward with -chugh

ghoj neHchugh jeSlaH

If (he/one) wants to learn, (he/one) can participate

I like the phrasing better in second person

Daghoj bIneHchugh, bIjeSlaH

or

bIghoj bIneHchugh, bIjeSlaH

I think these last two convey your sentiment the most exactly without sounding terribly awkward in Klingon

-be''etlh