Congratulations on the new position!
The answer(s) to that question depends a bit on what kind of tech lead role you will have. In my experience the term “tech lead” isn’t as universally defined as many other roles and I have seen very different roles all have the name tech lead.
In most places I have experience with, a tech lead role is not a management position, rather that is a separate tech/engineering manager role but it sounds like it’s included in your role description (at least in the future).
Which other responsibilities are included that you know of?