I got a text with heyaaa and my first name also.

The SMS can download malware onto your phone to copy your sim card (so they can clone your account, to make calls at your expense); photos (to disguise their identities in criminal transactions or use in romance scams); phonebook (to scam your friends and relatives); or bank information. You could also find that you have been subscribed to a third-party provider unknowingly, that will send you premium-rate text messages with no posted link to unsubscribe.
Your best defense is to delete the SMS without replying, and have your service provider block international calls, third-party providers and premium SMS.

Got a text saying heyaaa and my name and nothing else.
This is a variation on other calls other people have received from other phone numbers,so it is obviously some kind of spam or scam.
What is the purpose,though?
What does the idiot sending this gain?

I also got a call from this number and the text had heyaaa and my first name.
Nothing more.