The reason your trades start negative is because of the spread which is the difference between the Bid (Sell) price and Ask (buy) price. If you open a buy position at ask price, then you must sell at the bid price to close it. If you open a Sell position at bid price, then you must buy at Ask price to close it.
CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. 72.7% of retail investor accounts lose money when trading CFDs with this provider. You should consider whether you understand how CFDs work and whether you can afford to take the high risk of losing your money.