Washington is preparing for unrest, and planners urge people not to attend during a pandemic, but virtual events are intended to keep up the spirit of celebration.
Joseph R. Biden Jr. will become president of the United States at noon on January 20. The planners have announced a scaled back ceremony due to the pandemic.  The inagural committee will keep some of the traditional elements of the event while downsizing and “reimagining” the celebration which will be streamed live. 
Here’s a guide to the event.

Mr. Biden will be sworn in by Chief Justice John G. Roberts Jr. on the Capitol’s West Front at noon. The new president is then expected to give his inaugural address and conduct a review of military troops, as is tradition. Two major celebrities will participate in the swearing-in ceremony: Lady Gaga will sing the national anthem and Jennifer Lopez will give a musical performance.
Instead of a traditional parade on Pennsylvania Avenue as the new president, vice president and their families make their way to the White House over a mile away, there will be an official escort with representatives from every branch of the military for one city block.
For remote viewers, the inaugural committee has planned what it is calling a virtual parade across the country featuring music, poets and dancers “paying homage to America’s heroes on the front lines of the pandemic.”
At 5:30 p.m, the committee will hold a lighting ceremony around the Lincoln Memorial Reflecting Pool in remembrance of people in the United States who have lost their lives in the coronavirus pandemic.
Instead of the ball after the ceremony, there will be a prime-time television event at 8:30 p.m. Wednesday hosted by Tom Hanks and featuring celebrities including Justin Timberlake, Demi Lovato, Ant Clemons and Jon Bon Jovi.
On Friday, the inaugural committee named additional artists who will take part in the television special: Foo Fighters, John Legend, and Bruce Springsteen, who will perform from locations across the country.
Washington has been preparing for the possibility of protesters. The alert level of nation’s capital was elevated after a violent mob breached the Capitol building and forced lawmakers to halt the official counting of Electoral College votes to affirm Mr. Biden’s victory.
Mayor of DC Muriel E. Bowser has warned that extremists who support Mr. Trump might continue to wreak havoc and she extended the city’s public emergency through Jan. 21.
The F.B.I. and Secret Service have ramped up security efforts around the inauguration. Experts have warned that some far-right extremist groups are already discussing an assault on Inauguration Day similar to the deadly attack on the Capitol.
Breaking with tradition,  President Trump announced that he would not attend Mr. Biden’s inauguration. Mr. Biden called that decision “one of the few things he and I have ever agreed on.” Vice President Mike Pence will attend, after Mr. Biden made clear that he was welcome.
George W. Bush, has confirmed he would travel to Washington for Inauguration Day, along with Laura Bush, the former first lady. Barack Obama and Bill Clinton are also expected to attend, along with former first ladies Michelle Obama and Hillary Clinton. Jimmy Carter, who at 96 is the oldest living former president, announced that he and his wife would not attend.
This year tickets are not available to members of the public. Planners are urging people to stay home and participate in virtual inaugural events to prevent large crowds that could easily spread the coronavirus. Events will be live streamed. 
The Importance of the Inauguration Ceremony
The 20th Amendment to the Constitution requires that the term of each elected president and vice president begin at noon Jan. 20 of the year after the election. Every president has taken the oath of office, and they cannot assume their positions without doing so.
Symbolically, it marks the peaceful transfer of power from the current president to the next. Inauguration Day will be all the more important this year, as Mr. Biden ascends to the presidency at a time when political division has threatened the nation’s democratic institutions and his predecessor has gone to extreme lengths to stay in power.The inauguration is also a notable fund-raising opportunity for the incoming president. 

Source: NYT (Edited and condensed)