How do I go about this

I was diagnosed with ADHD when i was younger, like 15 or 16 years old, I was given vyvanse but I stopped taking it after a few months cause it felt a little too intense for me, but it did work INSANELY well for getting me to do things. I've been considering trying it again, or a different stimulant that is maybe less intense.

I don't currently have a family doc or an active prescription, I don't think I even remember the pediatrician I had at the time which was prescribing for me... How does one go about getting medicated again after many many years? I am 25 now so it's been about a decade.

Do I just make a random doctor's appointment, tell them I was previously diagnosed with ADHD and prescribed Vyvanse and ask if they can renew my ancient prescription? Or do I have to go through getting a formal assessment again? I don't really know how to provide proof, and I don't really know who I need to go see in particular.