I would focus first on getting to a general health level. If you are lifting moderately and are still sore, you need to get to a point where you are a lot less sore before you take on more.
Sarah would know more about specific competitions, but it might be good to start with a general level of fitness and healthy eating before doing anything too rigorous or strenuous.
While being motivated is good, being so sore that you can't work out is not. Unless this is just your first month (you will ALWAYS hurt your first month), you are probably hitting it too hard if you can't go the next day and at least do a little cardio (walking, running, elliptical, etc.).
You also need to figure out a plan, and that should govern what you do each week. You can change up your workout every month or so, which should prevent your body from adapting and should increase weights with your muscle growth and fat loss. I wouldn't do "whatever," as you may overdevelop some areas, overtrain others, and undertrain some. You won't have body equivalency, which is very important for balance and a nice lean look.