My 2cents: to lower the onboarding, would be great to set it to get notification about what /would/ be bought or sold; eventually users will trust the system and move some of their money to it.
If you follow the advice and record the trades you would have made, you can get an idea of if the advice is solid, and you can also get a hang for not panic-selling your first dip due to new-investor jitters. It also means that you won't follow crazy trends (like impulse-dumping everything into GME) because it's so obviously an outlier that it won't give you any useful data anyway.
When I was in high school there was a faux-stock-trading website, they gave you ten thousand dollars in fake money and you could fake-buy stocks with it. A great way to play around with, and learn about, the stock market with zero actual risk or investment required.
I ended up putting everything in Diamond Multimedia at $5 and pulling it out the next day at $6, then dumping the rest into eBay (within a month after their IPO IIRC) and forgetting about the website until one day I logged in and my investment was 10x. I patted myself on the back and never invested anything in anything again.
And one "trick" for backtesting is overlay SPX or SPY or DIA (or other favorite) with the results. Maybe it's obvious but folks new to the game are really helped by a comp to the market visual.