If you do take too much, share with another student, or if that is not possible, ask the instructor for correct disposal methods. Also ask about correct spill cleanup procedure. Be sure there are no flammable liquids around before lighting a bunsen burner. Do not point the mouth of the test tube towards yourself or your neighbor when you are heating a small amount of liquid in a test tube. Stir liquids with stirring rods, not metal spatulas.
Many chemicals react with metal.
Don't use force on glass tubing or glass stirring rods. Also, hot glass takes a long time to cool, and looks just like cold glass. Know the location and use of fire extinguishers. Read any instructions available for their use. Pull the pin before carrying the extinguisher.