Step 1:
Today is the day you face reality for the rest of your life. Your first photographs will never, ever, ever, EVER be your best shots. Hell, your first 500 shots will not be your best. It takes time, time, TIME to develop your own style as a photographer. Remember that, and you'll grow immensely as a photographer.
Step 2:
Always shoot in RAW format! If you're thinking about posting photos to Instagram or Face Book and your camera has the option, you can shoot in RAW + JPG. For clients, you'll always want to shoot in RAW format unless the client wants JPG. RAW format is easier to edit with less noise in the photos. ALWAYS SHOOT IN RAW FORMAT!!
Step 3:
Always bring back-up batteries with you. You camera is your life and your life will be hectic. With that said, you might leave your camera on when it's not necessary when you're talking with guests and/or your clients, and that will drain your battery. Make sure you have back-ups, a charger for the batteries and a mobile charger that hooks into your vehicle.
If you remember these three steps above any others, you'll succeed as a beginning photographer.
-VWP