• Travel can be used as a noun and as a verb.
• As a noun it is an uncountable noun and it is commonly used as a part of compound nouns.
Air travel is much cheaper than it was in the past.
His travels abroad provided lots of background material for novels he wrote.
(We can't say a travel, two travels because it is uncountable.)
• As a verb is the action of moving from one place to another place.
I would like to travel to Australia.
On holidays I usually travel to the sea.
• Journey can be a noun and a verb.
• As a verb has the same meaning than travel.
He journeyed/ travelled through the forest to the Mayan ruins.
• As a noun, it refers to travelling a long distance, or travelling regularly, emphasizing on the idea of travelling itself.
Plan your journey on the London Underground.
We had a long journey through the mountains.
He usually reads the paper during the trainjourney to work.
• Trip is a noun and it is used when we refer to travelling a short distance, or an unusual journey, emphasizing on the place or the reason of travelling.
Our last trip was to Paris
It's his first trip abroad
His job involves a lot of business trips.