Google Contacts by default orders contacts in each group / label alphabetically. Because Google knows better than you what you need there is no sorting option or any other way to change it.
However, if you need certain contact to appear always as first (even if its name doesn’t start with “a”) there’s a small workaround to Google stupidity.
The idea is to add
+ (plus sign) as Phonetic first (name) to such contact. You can get access to this field after clicking Show more:
Google Contacts gives Phonetic first field bigger priority than to First name and any contact that has anything except empty value or space in this field will appear over all other contacts.