As the direction of your trade depends on your expectation of the price in the future, you will enter a long position, i.e. you buy, if you anticipate rise in price. Alternatively, you will sell, if you think the opposite.
Spread betting is a form of trading derivative instruments, meaning that the price is derived from the underlying market. They give you the same exposure as if you were trading the underlying itself, hence all price movements and corporate actions (dividends, stock splits, buy backs) if applicable, will be reflected in your positions. They will never, however, result in the physical delivery of the underlying asset.