from typing import List


def get_prefix(text: str, prefixes_: List[str]):
    """
    If a text string starts with a substring, return the substring and the text minus the first instance of the
    substring; otherwise return None and the text.
    """
    for prefix in prefixes_:
        if text.startswith(prefix):
            return prefix, text[len(prefix):].lstrip()
    return None, text