If you're worried about diving straight in at the deep end with investing, but you're serious about doing it, then dummy portfolios let you build up your confidence first.
A lot of the platforms these days have 'dummy' or 'virtual' portfolios you can practise with. You trade exactly as you would if it were real, except you're not actually exchanging any money or buying any real shares, so if you do make a mistake, there's no harm done.
You have to be an existing investing customer with some companies first before they allow you to set up virtual portfolios alongside your real ones.
Have a look at our research section, which has a lot of good info for beginners, including a few companies that'll let you set up a virtual account.