https://hellhades.com/raid-shadow-legends-promo-codes/

This should have an up to date promo code list ... hope it helps !

Link Codes, how do they work? I created an account yesterday, would be cool to use these but do they mean it is a one time thing on a brand new account or, what is the deal?

You can only use promo codes once, but any account can use them. To use the codes, you click on the popup on the far left of the Bastion, and click on the Promo codes tab. There you can enter a code. But im not to sure i understood your question correctly.

Yeah this I know, but there are the "Link Codes" too, I tried to use one, but It dosent seem to work. I guess it is only when creating a brand new account not when having a brand new account. 

ANY active promocodes? seems all are invalid atm :(