Which skateboard to buy?

Hey Guys im 14 years old I live in the UK i have a Local Skate park which is very CLOSE i really want to get into Skating i don't know much like the sizes i should get remember im only 14 so i wanna Buy something pretty cheap to begin with like £20-£30 But what sizes should i get and stuff thank you guys My shoe Size is 9 And i saw this what do you think http://www.argos.co.uk/static/Product/partNumber/9350414/Trail/searchtext%3ESKATEBAORDS.htm