This can be everything from really small over normal or big to huge. The system is capabale to deal with different account sizes. The minimum risk in lot that you can use is 0.01 lot. The maximum risk is often defined by your broker and sometimes ends up at 50 or 100 lots in an instrument per trade.
More normal settings are often 0.05 or 0.1 in lot sizes, but we also used 1 lot, 2 lots, 4 lots or 8 lots to constantly trade with it. Depending on your leverage and your broker Margin requests you need to have the equivalent amount of money on your account.
Beginners should not trade with real money at all until they are aware how the system works, which position sizes will be opened when certain lot sizes are chosen. Go to your broker and book one, two or more demo accounts and start demo trading to get a feeling for the system. Give those demo accounts different money setups like 1,000 USD or 5,000 USD and then start testing out how big the positions will be if you are dealing with 0.01, 0.05, 0.1, 0.5 or 1 Lot. Or everything else in between, whatever you like.
Yes, Demotrading is an invest of time and money, but absolut necessary since it builds up the practical experience that you will need to get along with the complete setup.
Once you have the feeling start small. When starting with 0.01 lot there is not much to loose. You slowly can then increase the risk depending on your settings and your experience.
The risk is always on you. We never take over risks from software users anyhow, since we never know what they are doing with this software. The software will be a blessing for those who are experienced and use it in the right way. But the software can also be very dangerous if you are using it wrongly you are able to loose a lot of money. So be careful, start small, unless you have a whole lot of experience with automated trading and Expert-Advisors in general.