My advice for reporters and protestors visiting Donald Trump events is simple: You have a right to keep and bear arms. Use it. If Trump's brownshirts know their targets are armed, they'll get less handsy, fast.
For those who want to carry a concealed weapon for personal protection, NRA offers classes on handgun safety, and NRA-ILA has detailed information on state gun laws, including which states have permit reciprocity agreements with other states.
Traveling to another state for an event? Here are TSA's rules on transporting firearms.
And lastly, when attacked by a Trump goon, if you're hesitating to defend yourself with your firearm, ask yourself whether it's better to be tried by twelve, or carried by six.
Update: Obviously should any of Trump's events be declared gun-free zones, obey those laws as well.