These are verbs of motion in the imperative forms, yes?

Note that they are both the prefixed perfective forms from the verb идти 'to go'. In situations like this, it helps to study prefixes and what they mean:

в(о)- meaning enter (motion into)

за -can represent the beginning of a repeated motion, a short visit to somebody or some place ("dropping in somewhere")

I hope this helps you understand the verbs in the context you are pulling them out of.