Before investing you should consider:
Setting aside enough money in accesible savings to cover any emergencies - an amount of around 4 times your essential monthly expenditure is typically about right.
If your existing insurance and pension arrangements are sufficient for your needs.
Paying off any high interest debts that your money would be better used to repay.
If you can afford to leave your investment untouched for at least 5 years - there's no minimum term you need to hold your investment for, but you should only invest if you can afford to leave the money you invest untouched for at least 5 years.
If you can afford to lose money - the value of investments can go down as well as up, unlike deposits in savings account, for example. This means you could get back less than your original investment.