You should expect around a minimum hold time of two to three years. It is possible to see a return earlier, but angel investing can take time.
Please note that it is okay to change your mind! Platforms generally offer a short period directly after the investment is made (typically 48 hours) to cancel. After that, you may be locked in for a year before you can sell your stake if you decide that startup is not for you. If you are on the fence, make sure to double-check the policies of the crowdfunding platform before you invest.