That's a good approach
Have fun!
Re "but even second hand a good tent or bag is dear if its a mistake": Perhaps, but you''ll learn from it (what do you like/dislike, why is it unsuitable). Unless it's a disaster, e.g. very inappropriate for the weather, you can keep it to benefit from until you choose your next model, then sell it on. Of course, you can learn heaps from renting/borrowing gear too