Personally to me i would not cast two spells at once, because to me it would feel unbalanced energy. I don't really it is a good idea to cast two spells at once, but its just my opinion. Only do this if you the spells do work and are not some spells that are made up, or are fluff spells.
Make sure you know your basics of magick, espically being aware of your energy, Energy is what causes a spell to work. It takes a lot and it sometimes takes a while to happen depending on the experince of that caster.
Your basics should always be handy, meditation, visualization and grounding/centering should be practiced daily if you have the time in your schedule.