Wiktionary
dip a toe into
vb. (context idiomatic figuratively English) To enter or get involved in tentatively and for the first time.
Usage examples of "dip a toe into".
It was big and it was out there, and sometimes it was an invigorating thing to dip a toe into, but you couldn't live in it all the time.
I see them all, flowing past me like so many rivers, and I can dip a toe into any of them I please.
But she hovered on the edge of the pool, so to speak, unable to dip a toe into the water, let alone start swimming.