Hi PK – the great thing about the Internet is that you can quickly become an expert in anything in a very short time if you put your mind to it. Choose almost any topic research of two or three hours, make notes, and you will probably know more than 90% of the population.
The fewer the number of people interested in that topic, the more this will be true.
If you want to write travel articles or create a travel site then simply go and have a look at travel websites check out lonely planet and the rough guide websites. Gather together the information on a particular place, and your spin, and there are the main elements of your own article or site.
If you want to have a website then host your own one by installing WordPress. For an expert this is a 5 to 10 minute job – for a new, just google it it's pretty easy. Hosting your own WordPress site will cost you around about $10 for a domain name, and may be $70 a year for hosting (Hostgator).
If you want to go free, then grab yourself a blog at WordPress.com and get going there.
I hope these suggestions help.
Best wishes, Malc