To be honest, i know Chonky is trying to be helpful, but there is a lot of information out there on stocks and to be honest, it can be a lot simpler than that.
Picking individual stocks is inherently risky. Some companies can boom, but equally, they can go bust over night. If you only have a small handful of these companies you have a large risk of something going wrong.
You also have to factor in that, lets be honest, we don't have any inside information or huge knowledge of the companies and we are likely to pick names we know, hardly a quick way to success.
I don't have any particularly products to recommend you, but the sensible way to buy the stocks is through a stocks and shares ISA. That way, you dont have to pay any tax as the profit you have grows, and there is no cost to take it out of that tax wrapper.
Having said that you shouldn't pick individual stocks, my personal feeling is the best way to maximise your potential profit is to invest in trackers or index funds. These pick small amounts of stocks in 1000's of companies across a particular sector or market, therefore if any of those companies fail they are only a small portion of your overall basket.
Personally, i use Vanguard Lifestratergy products, which only have a 0.2ish percent charge and will generally perform in line with the tracker they are following. Please do your own research, but the UKPersonalFinance subs on Reddit are a great place to start.