Very new to this and looking at trial

Hi there.
Thanks again for all the helpful replies. I was wondering with the default settings (let’s say I stuck with the 30%), when people say a downswing that doesn’t mean that their bankroll goes negative does it?
I mean let’s say I started with £1000 and I had a bad downswing it wouldn’t mean I’d have to put more in to the bank would it?
I’d really like to give this a really good shot but can only put in so much that I’m willing to ‘risk’ so hoping that I would see a return before needing to add more to the bankroll? If that makes sense?

For instance on this post here -Negative Results After 3000 Bets - Improving

He says he’s got a negative profit. Does that mean that he’s had to put more into his bankroll at some point?

Many thanks