HELP ME!! SYNTHESIS!!?

Well first, you have to memorize the synthetic transformations, or else you wouldn't know what to do. If you have a table with you, that's helpful, too, but it's easier to just memorize it (that way you don't have to consult the table each time you think you could do something). Second, you look at your starting material and your target and ask "which synthetic transformation could I use to get to my product?" A lot of times, this involves looking at your target and working backwards to your starting material, but whatever way works.