Welcom to the board. The trick with triangles is that you just can't lay them on top of each other and sew that line. Instead there has to be a 1/4" overhang to get them to align properly. Good luck. You may want to start with Flying Geese or Windmills to get into the triangle world. HSTs (Half-square triangles are a bit easier to learn). Good luck and hang in there.