Hi Natasha,
There is an induction process for the laser cutter, then intention is that this is enough to use the machine safely on your own but not much more, however I'm happy to offer help when I'm around.
In general any 2D design file will work or can be made to work.
Illustrator (.ai), DXF or SVG are preferred.
Accessibility wise, we are not wheelchair accessible but the main workshop is mostly on street level, we have another workshop in the buildings basement which is down some stairs.
All the best,
Dan