I exchanged in the beginning without prevent losses too. But if you're wrong with your predicted price it may take till you reach T/P. So I started using S/L's and still have money to trade in the end of the day.
I began a trading account with $300 and lost $246 in matter of days just b/c of S/L. It might be possible to quit using stop losses when you're more experienced but as a rookie I'm sticking with them for now.