"Everywhere" as 到处都 or 到处都是 From this Mandarin Corner video:  https://youtu.be/2JttZXFJrNg?t=28

(Transcript provided on their website:)


  00:00:24,000 –> 00:00:28,000
  
  Dàjiē shàng hěnduō shù bèi guā dǎo le,
  
  大街上很多树被刮倒了，
  
  00:00:28,000 –> 00:00:31,700
  
  wàimian de lajī yě bèi chuī de dàochù dōu shì,
  
  外面的垃圾也被吹得到处都是，
  
  00:00:31,700 –> 00:00:34,166
  
  gēnběn méi bànfǎ chūmén,
  
  根本没办法出门，


I don't understand why "everywhere" can't be expressed as just 到处 there.  If I Google examples it looks like 到处都是 is an entire fixed phrase that means "everywhere", but if I look up 到处, 到处都, and 到处都是 they are defined as "everywhere".
到处是 can be used interchangeably as 到处都是 and they means something exist everywere.

For example, 菜园里到处都是蘑菇 means mushrooms are everywhere in the garden.

Sometimes, 都 gives significance to the sentence, it emphasis that this specific place is unique as it has a specific object everywhere. 

For example, 海里到处是水! means Ocean has water(which is a fact about ocean)
whereas if you say: 家里到处都是水 meaning there is water everywhere at home. You see that it is uncommon. 

是means to be. So if you wish to use another verb with everywhere, you should remove 是 and replace it with a verb that you want to use。

Example: 到处跳舞： Dance Everywhere.
到处逛： Wandering Everywhere。

Hope That help.