The excitement is good, but don't let it push you to make mistakes.
Make a plan - write it down - check it as you go.
Read the tutorials on making a first knife ( there is one in the stickys).
Take your time. Rushing to finish the knife in a day is the ruin of most first knives. Shoot for a week. Also, do only one knife at a time in the beginning. No point in making the same mistake multiple times.
Plan each step. Consider what materials and supplies you will need, how you are going to do that step, and when/how you will know it is finished.
Keep it simple. A first knife should be as simple as possible. A drop point hunter with a 3" blade and a 4" handle is perfect. A first knife is all about edge and handle. Guards, fancy shapes, whistles and bells, etc. can all wait for knife #10.
Don't limit the knife to the bar of steel. The tendency is to take the bar and make a knife out of that shape. This often ends in what I call a "sharpened bar of steel" look. If you only use 7" of the bar, so be it. Some time you will use the other 5". If the knife is curved, or less wide than the bar ... that is a good thing. New makers seem to feel they are wasting the steel, but actually, the steel is usually the cheapest part of the knife.
Draw a sketch of the knife you want to make on graph paper. Then trace the bar of steel shape around it. That will show you what you need to remove from the bar to get the knife. Draw that shape on the actual bar of steel. Many people reduce the sketch and glue it right on the steel bar.
Tip- The white paint type metal markers are the best for drawing on the steel. They stay on a long time ( even through HT), and are very visible. Places like Fastenal carry them, as does K-Mart and most craft stores. Also, write the steel type in the tang with one of these markers when sending the blade out for HT. Put your name or initials on the other side. Mark all bars of steel and cut off pieces with the marker to identify them later on. Do this immediately when you receive the steel and when you cut a piece off. Every smith who has been around a while has a pile of steel he doesn't know what it is because he was going to "mark it later".
Do all the steps fully . Don't skip ahead or say, "That's good enough".
Post your plan and photos of your progress here so others can help you fine tune any things that may cause problems later.
Make any detail or accent features last thing after the bevels and shape are done. Jimping, choils, tang holes, finger grooves, etc. These may need to be moved as you shape the handle and bevels. If you cut them in too soon, they may end up in the wrong place. These items are done last thing before HT.