I don’t think you can put a time on it but would like you have invest a little as you will have more of an emotional attachment to your own money which is another skill to control your emotions with it
I recommend beginners to start demo trading before going live. Demo trading will help you to gain the necessary experience and test the right strategies. After a few months, you will gain knowledge and will be able to trade in a real account.
In this case trader should take some risk to invest some more capital in trading account. 1 year is enough time period to have experience on small account. If you are not successful yet , change strategy and have a courage to trade with more money. Time and success level both are important to go to live account from demo account.
I’ve spent quite a lot of time practicing on a demo account about 6 months in total then moved to opening a small account to practice trading with actually money. When did you feel comfortable enough to invest a substantial amount into trading ?
I don't think the time can be fixed and same for all. It all depends on how well versed a beginner is with the basics and his/her skills of trading and handling the market pressure. Demo trading is helpful of course, but the time period will vary for all traders.