What to Know About the Republican National Convention: Day 1

As the Republican National Convention (RNC) kicks off in Cleveland today, there are three key questions on everyone's mind.

Will Donald Trump Speak?

Donald Trump said he will be at the RNC tonight to watch his wife Melania Trump speak. The presumptive GOP presidential nominee isn't scheduled to deliver remarks of his own until Thursday night. But, during a call-in interview this morning on Fox News' "Fox and Friends," he didn't rule out speaking tonight as well.

"Well, I may speak up. To be honest, I want to see this," Trump said when asked if he would be addressing the convention with his wife. "I'd love to be there when my wife speaks. So the answer is yes, I will be there."

The rumor in Cleveland is that Trump will be introducing his wife.

"This is Donald Trump's convention and he's going to do it his way," ABC News' George Stephanopoulos said today from Quicken Loans Arena in downtown Cleveland, the site of the convention.

Campaign Chairman Paul Manafort confirmed that Melania Trump will be addressing the convention on the first night of the event.

Sources tell ABC that the former model and Trump's third wife spent the weekend preparing for the address in New Jersey. The campaign has released no information about what her speech will focus on or how long it will run, but they did not rule out the prospect of her husband making an earlier-than-normal appearance at the convention in order to introduce his wife.

Will Cleveland See Convention Unrest?

So far, there have been largely peaceful demonstrations in Cleveland. But the Ohio city is bracing for the worst, as recent domestic and world events have heightened security concerns in the days leading up to the RNC.

"This city is prepared for that, but it's also a city on edge," Stephanopoulos said.

Thousands of law enforcement officers were ordered to Ohio even before the fatal shootings of police officers in Baton Rouge, Louisiana. More than 3.5 miles of security fence line downtown Cleveland and a total of 5,500 officers, many from out of state, have been assigned to convention security.

But after yet another tragedy, the head of Cleveland's largest police union called for an emergency action to be taken to ban the state's open carry laws during the convention.

Still, Cleveland Police Chief Calvin Williams said officers are "prepared for anything and everything" that could potentially happen.

What About Unrest Inside the Convention?

There's concern that the "Never Trump" camp, a group of some Republicans and other prominent conservatives aiming to prevent Trump from obtaining the party's presidential nomination, will disrupt proceedings at the convention this week.

"The Trump team is confident they're going to be able to shut them down. But there's a lot of people on edge about that as well," Stephanopoulos said. "In fact, when I talked to the RNC Chair Reince Priebus yesterday about that, he seemed pretty irritated by the 'Never Trump' forces."

Priebus warned that disturbing the GOP convention proceedings would only help the presumptive Democratic nominee Hillary Clinton.

"If [they] want to delay the proceedings, all they're doing is delaying the evening and helping Hillary Clinton," Priebus said on ABC's "This Week" on Sunday. "I'm not going to just shut people down," Priebus said of delegates who may try blocking Trump's nomination at the convention. "But I'm also going to make sure that our rules are followed. And I don't think they're going to be successful."

The party chairman said that "Never Trump" delegates need to recognize that voters have made their choice and that opposing Trump now amounts to support for Clinton.

"They don't like the idea that 14 million people...picked someone that they didn't want," Priebus said, adding, "It's a binary choice. It's either Donald Trump or Hillary Clinton."

ABC News' Meghan Keneally and Nicki Rossoll contributed to this report.