The biggest decision you have to make is how much you can afford to risk and to know how long you want to invest for. My advice would be to take a small risk to start and see how things go and then you can increase your investment once you can see the results.
Individual stocks are popular at the moment. For beginners Loyal3 are good as they allow investors to buy small shares and there is a choice of over 70 companies. You can purchase from as little as 10$ which is a good way to start and learn.
Age is a big factor to take into account with investment. Longer term, higher risk investment options are usually more attractive to younger people than older people so it depends on your circumstances and the amount of time you have to get money back.
You should consult a professional, a financial advisor, accountant or a tax specialist can advise you about the tax implications of particular investments which relate to your own circumstances.
ALWAYS seek professional advice! If this is not a field that you are familiar with then you could easily be burnt! Remember that there are always plenty of people out there who are willing to take your hard earned cash out of your hand. Be safe and good luck!