How to write a regular expression with a specific pattern?

Question

Regular Expressions

The essence of the question is this. I can't figure out how to make the regular expression process this pattern:
The first character can be a letter or a certain character, and then letters and numbers are allowed, as well as other allowed characters.

So far it turns out like this: I can’t understand how to make sure that the characters after the first character are checked separately.
match(/^[A-Za-z:.,_/-]{1}/)

Answer 1

What do you mean https://regex101.com/r/ROjnM2/1