Hey, there are multiple ways to get keywords. I'll list out a few here:
1. Google's Keyword planner tool - search for website/niche specific keywords with metrics such as monthly search and competition handy.
2. Ubersuggest by Neil Patel - You can search for your competitor's domain, and check the keywords they're ranking for. This is an easy way, you can just piggyback on their effort and boost ranking.
3. SEMRush's Keyword Overview tool
3. Google suggestions - In the google search toolbar type "travel to " and see the suggestions in the dropdown menu. These are the terms people are searching/talking about.
4. Quora - Type your main keyword in the search bar, and check for the questions people are asking. This is a good resource to find highly searched terms.
Your final list will comprise of an ordered list of keywords that you found from all of the above efforts