I went from cart to straight and didn't kill myself. Didn't even really cut myself. Go slow and careful, make sure the angle is right, make sure the straight truly is shave ready (a lot are sold that claim to be and aren't). Some people will tell you that you should use your dominant hand for both sides of the face, others say to switch hands when you switch sides. Do which ever makes it easier for you to get everything. First few time, don't go for perfect, just for good enough. If you really feel the need to get that last little bit of stubble, touch up with the DE until you really get a feel for the straight.
Looking to try a straight