TRAVEL
Travel is a verb most of the time.
When you use 'travel' as a noun, it is an uncountable noun, which means that you use it in the singular without an article. It refers to the abstract concept of travel. You can't say 'a travel' or 'my travel'
I love foreign travel.
Travel sometimes occurs in the plural in a phrase such as 'This is a book about Livingstone's travels in Africa'. This is quite unusual.
JOURNEY
This is a countable noun. It refers to going from one place to another.
That was a tiring journey.
What's the longest journey you've ever been on?
How long is the journey from London to Paris
TRIP
This is also a countable noun, but it often refers to your journey to a place, the time you spent there, and your journey back.
eg a round trip
How was your business trip to New York? Did it go well?
We went a weekend trip to Rome.