In my experience, above all else understanding your own and the market's behaviours to (either positive or adverse) price movements - controlling yours, and predicting others' - is the key to successful trading/investing. Possibly the two most important cognitive behaviours to understand and work on are loss aversion and confirmation bias.
Of these, even after a good number of years of trading/investing I still find myself either taking some losses or else cutting short my profits due to loss aversion. The fact of loss aversion - that we prefer to avoid losses to acquiring equivalent gains - is the reason why trying out 'virtual' portfolios is actually not a great idea. When there's nothing to lose, why not slap a hundred quid on a share to see what it does? And if it comes in, slap the profit around and see if those multiples really grow. If the bet comes off you're a genius; if not, no matter, there's no pain.
When it comes down to gambling on the markets for real, loss aversion means that you are less likely to slap that hundred quid on that share, but instead a tenth of it. Yes, it may come good, but your profits grow are much slower rate (which can get frustrating so lead to more risky behaviour) - vs. if the share halves, such is the felt loss aversion that you sell it. Not only that but loss aversion means that your next bet is just 5 quid, not 10, but now you have to get back not only the tenner you lost but also try to find profit on top.
In real life what this merry go round teaches you is to be patient. If the reasons why you bought the share still hold, then hold. But then you might fall into the loss aversion paradox of 'doubling down' - buying more shares in the company at a lower price, to lower your average price paid per share, but more of them and so more risk. You're now starting to stretch that investment pot such that you don't have much you can be elsewhere to catch profits elsewhere. And so on.
You might start of with the intention of buying a passive fund that tracks the market, so earning a few percentage points over the rate of interest over the long term, or buying a share in a ftse 100 that waxes and wanes and waxes slowly, whilst you pick up a small divi from it. But then the hunger for quicker profits comes in, so you hear about the Alternative Investment Market (AIMS) and the money to be made on penny shares, many of which are run by shysters who simply rinse the punters year after year. That game can be won by understanding how other private investors react but again, you'll have to keep your loss aversion in check. If a punt doesn't come off, don't double down or perhaps just hold the share for the next pump and dump that comes round yearly, and so on.
Unfortunately, there is no substitute for real experience. And it can costly getting that experience. I think you have to think about whether you simply want to own some trackers or maybe some blue-chip and let it ride long term, or else dip into the massive amount of online help and knowledge is there is around to begin understanding the markets, and maybe put a little aside to gamble, say, on a AIM market share. By following your blue chips and/or AIM share, you'll learn loads both about the company but also about market behaviours, as well as learn a lot about yourself. The latter is the most important. If you can understand your reactions to share losses and profits and are able to begin to rationalise these and act accordingly, then you'll dramatically improve your chances of success.