You need your spokes to be tight. You also need your wheel to be true. Therein lies the art of wheelbuilding.
A truing stand is not necessary but it sure does help! I've built lots of wheels. No reason to be scared of your spokes, just work a little bit at a time.
Before you do anything, check out the feel of all the spokes on the wheel. They should have a certain amount of give, but they should also be tight. If you need a rough idea of how tight they should be, run to a real bike shop and press on the spokes of a traditionally laced (3x) wheel. That should be a good indicator.
Usually, spokes will loosen during use meaning that any change to spoke tension will come throught added tension. If you notice any really loose spokes. tighten them a half turn - maybe even a full turn. If you have lots of loose spokes, it is safe to tighten them up in half turn increments. Remember that tightening spokes brings up tension on all the spokes as it is a closed system. Work from worst wobble, tighten the spokes that pull there, find the next worst wobble, work it there, etc. etc.
After you get your true, work for round, then do a final turn or two for true.
Sometimes you will notice a spoke has very high tension but isn't pulling the rim enough. In those situations, you need to release tension on the other side.
When you are happy enough with your truing of the wheel, work around the wheel with your hands, squeezing all the spokes tight. You won't break them. This will relieve the stress on the spokes you put in while truing them.
A strong, reliable wheel has tight spokes. It is the looseness in the spokes that allows movement (usually in the j-bend) when the tension releases in the turning and, over time, the metal will fail.