If you're just starting out in this event-planning thing, it may not be entirely obvious that you need to protect against any possible damage or injury resulting from your show.
You do. Event insurance is easy enough to come by, and it's worth the investment. This type of insurance will protect you should (certain) things go wrong, such as a stage mishap. If the stage you rent turns out not to be able to handle the weight of all that music equipment, you could be on the hook for some serious cash unless you have an insurance policy to cover the damage.
You also want to make sure any contracted workers or entertainment have the proper insurance, too. Otherwise, you could end up paying for their mistakes.
Next, before solidifying your plans ...