Garage Rendering Internal Corners

Hi all,

I am looking to render my garage internally on the walls.

I will be using a one coat render. I have 2 brick supports either side of the brick walls (see image) that would need rendering also. I realise I need to use beads for the corners of the supports, would I need them on the both the internal & external corners of the supports? Or just the External ones. Can you also recommend some from Screwfix?

In regards to sticking the beads to the wall, what adhesive shall I use? Again can somebody recommend one from Screwfix?

Thanks for reading .