Welcome to Curiosity @vishnu. For a beginner, it’s obvious that you will find it hard to compose your subjects inside a frame. Indeed, the composition part is usually the biggest variable for any shots. Most of the times, I use the rule of thirds, as it draws attention quicker (and aids as a visual guide for leveling). Ultimately, you will realize that any rule is good! If the subject is captivating, all you need is to capture it in the most beautiful way in which your mind tells you to. Consider that the rule of thirds, the phi rule (golden ratio) and other rules are there as helpers or as guidelines. They are not actually rules per se. The best way to learn photography is by experimenting stuffs. :) Good luck.
