“It can be tough to navigate the sea of information that's out there these days.”

Your company sells guides that other businesses use to decide which equipment to buy. You 're writing a sales letter to send to potential customers. You want to explain why they need your guides. You write:

It can be tough to navigate the sea of information that's out there these days.

It can be tough to (do something)

Write about something that's difficult for people to do this way:

It can be tough to find time for exercise, but it's extremely important for your health, as well as your mood.

You can also write "it can be hard" or "it can be difficult".

navigate (a sea or ocean)

The word "navigate" means to find out where you're going on a boat or ship. When people used to travel on wooden sailing ships, people navigated using maps, the position of the stars, and a compass.

These days, people don't talk much about navigating the ocean. Instead, people use "navigate" in metaphors like in the example above.

When a person rides in a car and tells the driver where to go by looking at a map or GPS, they're also "navigating" the car.

the sea of information

People often compare information to the sea, because there's so much information available these days. You can imagine that each piece of information is one drop of water. 

You can extend this metaphor by saying things like:

I'm drowning in a sea of information.

We're all adrift in a sea of information.

(something) is out there these days

Things that are currently happening in society are "out there these days".

You can talk about crime this way:

There are a lot of dangerous and sick people out there these days.

Or you can talk about the economy:

Things are tough out there these days.