Answer
How do you start a crowdfunding campaign?
Short answer
You describe what you are making, set the amount that makes it possible and a deadline, and say what backers get. There is nothing to pay to open a campaign here — the fee comes out of what you raise, and only if you raise it.
The part that decides whether it works happens before you write anything: pick a goal that is the real cost of the thing, not an aspiration. This is all-or-nothing, so a goal set high to look impressive is a goal you can miss by a euro and receive nothing for. The number should be what you genuinely need to deliver what you are promising, including the part people forget — shipping, packaging, the fee, and the tax on the money once it is yours.
Then the reward. It has to be a specific thing with a described state, not a gesture. “The finished product, posted in March” works; “our eternal gratitude” does not, because it gives a stranger no reason to prefer you to any other campaign. If you are unsure whether a reward is strong enough, ask whether someone who has never met you would pay that amount for it on its own.
The page itself is mostly evidence. A short video of the thing existing beats any amount of copy about the thing being planned, and a photograph of a rough prototype beats a render. Backers on every platform have learned to distinguish those, and the ones who have been burned before are looking specifically.
Practically: an account, the campaign details, a cover image, a video if you have one, and the reward. It goes live once submitted, the deadline runs from there, and you can post updates throughout — which matter more than most creators expect, because the campaigns that fund late are usually the ones whose backers had a reason to come back.