Here is a jam board where students anonymously posted what they think a safe space feels, sounds, and smells like.  

https://jamboard.google.com/d/1KKnl-wUcAzIC33t91jvyAoB3t0VLSwZH9meR9tcld_w/viewer

Here is an example survey to gauge how your students are feeling:

 https://docs.google.com/forms/d/e/1FAIpQLScQO6b4htI9KB9obnODvLPh1hUBc0c_65a8QCWEw0Oh6P868A/viewform