Making healing potions requires an Herbalism Kit and proficiency with one. I don't know if you're allowed to have the kit since we all started broke as hell, but you get a free Tool Proficiency, so you're allowed to use it if you have one.
You'll need to roll either Survival(Wisdom), or Nature(Intelligence) to gather and identify the ingredients, and a Nature(Intelligence or Wisdom) + Tool Proficiency to craft a single potion.
(Normally it would take 25 gp and a day of work to make a potion. I'd allow you to waive the gp cost since you're collecting the herbs manually, and time... is a little weird here. So we'll need someone else to rule on that.)
Not sure this is acceptable for this game, but that's how I'd handle it RAW.