Seconding Pete on GHK-Cu for your goals. I started with it about 6 months ago and it was a really smooth introduction to the space. Low complexity, good research base, and you can stack it later once you’re comfortable.

One thing I’d add: take before photos on day 1 and again at week 4 and week 8. Skin changes are subtle and gradual – you won’t notice unless you’re comparing side by side.