A share, or stock price is the given amount that it costs to buy one share in a company. In general the price of a share is not fixed, but fluctuates according to market conditions and shares can be bought from a wide number of publicly available platforms.
The price of a share is subject to a number of factors, including market volatility and conditions in the given sector at that time. Given the level of market fluctuation it is always advisable to take expert advice but many platforms today will allow you to practice simulated trades prior to investing your own capital.