How small can you start with crowdfunding, and how do beginners usually spread their money?

Minimums differ by type. Real estate crowdfunding often starts around 100 to 500 euros per project. Startup platforms usually have no standard minimum: each campaign sets its own ticket size. Private funds for professional investors start far higher.
A lower minimum mainly lets you hold more positions with the same money: with 1,000 euros, a 100-euro minimum allows ten projects, a 500-euro minimum only two.
More positions alone is not diversification. Real diversification means variety in asset type, country and loan structure, and not keeping everything on one platform.
Two habits help most: read the key investment information sheet of every project before you commit, and do not mistake a low minimum for low risk. Capital is at risk: crowdfunding investments are not covered by deposit guarantee schemes, can lose part or all of their value, and may be hard to sell before the end of their term.