Compare watercolour and gouache for a beginner painting hobby

You have decided to take up painting and every art shop aisle looks the same to someone who has never picked up a brush. This lays out watercolour against gouache in terms that actually matter when you are starting out: forgiveness of mistakes, cost, portability, and how long before you produce something you like. One clear recommendation at the end.

You are thinking about taking up painting as a hobby and cannot decide between watercolour and gouache as a starting medium. Explain the practical differences between the two for someone who has never painted before: how forgiving each is of mistakes, how much it costs to get started properly, how portable each setup is, what kind of subjects each suits best, and how steep the learning curve feels in the first few months. End with a single recommendation for an absolute beginner who wants results they are proud of within the first few sessions, and name one starter kit or material list to look for. Keep the whole answer practical and specific, around 300 words, no flowery language about the joys of painting.