If you want to get your feet wet, maybe go with the index ETFs first.
Firstly, you won’t lose the whole £200, as the index would have to go to zero - and in that case the world must have gone to war or something far worse.
On a small amount of capital though, you won’t see big returns unless you were to pick risky individual stocks etc.
VUSA or S&P500 ETF’s are roughly 5% away from all time highs. You could just buy the market now and wait until those highs are reached, netting you £10 return on your £200 investment. I don’t know how quick or long this will take, but rest assured it will more than likely occur.
I don’t use Stop Losses, and more than likely never will. Others here do. It’s a personal choice to make, but I would advise that if you use them, not to set them too tight as they will trigger with normal stock fluctuations otherwise.
Hope this answers a few queries, if not just message me back