A straight razor from SRD is one of the best ways to start into straight shaving because you know there is no issue with the sharpness or quality. Everything mentioned above will help with the razor burn with prep, angle and pressure high on the list. It took me some time to get to the point where I could get to the smooth shave but it was worth the journey. You may notice razor burn in some areas and not in others. My problem was the areas on my neck and chin where I had to use peripheral vision. It was hard to gauge the angle and my grip made it hard to control the pressure. Note what you are doing in the areas you get good results in and try to maintain that technique in the other areas. Be sure to stretch you skin. Develop a technique that works for you and is comfortable. As you gain more experience you technique will change for the better.

Good luck