When i bought a mojang game card for my windows 8 pc

When I bought a mojang game card on march 2 2013, I had some troubles, First off a have a windows 8 PC/Laptop...and when I started my first survival world and well u know how it has a building terrain thing at the bottom with a loading green bar at the bottom I didn't have that....so then I started playing and every time I move or look or break, add, create, etc. I go slow..my friend does not have. Can anyone help me?