I’d stand there, not looking in their direction. Pretend I don’t notice them.
Then they can make the first move.
My original intention for doing so, is how I deal with strange children I have to deal with for some reason and quickly gain their confidence, animals I don’t know, and adults whose intentions I don’t know but might be hostile, might not be.
I just do whatever I’m doing, not noticing, but occasionally glancing so they know I’m noticing a little.
This way it gives them space to look me over, check me out, smell the air around me, decide what THEY want to do and how they want to approach me.
When they indicate their interest in engagement, then I will engage but slowly, just a little bit at a time.
Mind you, I don’t know HOW the aliens might engage.
I don’t know if they have amygdalas with fear type components that I need to be aware of.
But it’s all i have to work with at the moment that I know works among life forms on earth