Am I allowed to contact clients after leaving my salaried job as a travel agent?

Assuming you have no contract which limits your right to compete, and you were not an owner of your former employer, you can contact past and present clients, or compete in any other lawful way you see fit, EXCEPT that you may not use your former employer's trade secrets to do so.  In some cases, a customer list could be considered a trade secret, but if customer names are readily ascertainable from available information (usually including your unaided memory), they would not be a trade secret.