Hello, The thought of starting a blog is great. Your confusion is quite justified. My opinion would be write of your own experiences, how you felt in a trip, your learnings, any tips you would like to give.. etc. A personalized blog always has an edge over a generic text. The other reason is terms like top 10 places to visit are quite relative and what for you may be the best reason to visit a place may seem boring for someone else. Hence, write about your travels, it gives your readers a different view from theirs, look from a different perspective and sometimes even appreciate it. Hope my opinion helps.... Happy writing ....
Top 10 would be more appreciated. It makes people curious enough to read and also you will get to know more details and info about those places and others through your references and studies. Also try giving them an eye catching heading every time, so that it makes people to read the whole blog just by reading the title.
I would prefer to write about my personal experience, it's more helpful for others to comprehend. Moreover 'top 10 places to visit' can be obtained through different articles it's what your own thought matters the most.
hopefully this will help you to start your writing