It is study of nature.So whatever present this universe we learn physics from there.So if you take any phenomenon why it happened/happens?how it happened?if you can find answer to that probably it's physics.As humans we try to understand this and use for our own wellfare and use.Every machine ,electricity, a pulley every medical diagnostic instruments,mechanical parts in a factory,missile,space craft research instruments / labs and many more are application of physics

Fantastic. As you understand the concepts  and principles of physics in more details you feel more confident. You become more enthusiastic and will try to apply the laws of physics in ever aspect  of life just to explain yourself. You take great interest to teach  the laws of  physics to others. U fell like a science geek . 

Yes doing the research from home is possible. You have to keep in touch with the collaborators for writing or reviewing papers or proposals and this you can do with many online video conferencing app. You also have to be in touch with the university as well from where you are going to publish your research papers.  

Dear Renu, other than all practical advantage of learning Physics, it gives you a completely different and better ideas for dealing with problems in life. You try to find out solution rather than suffering from them. 

One not so good point is that you could see and realise how natural phenomena is happening around you and it makes you miss the beauty of it. But it's all upto you to choose your view to see world. It's good to be ignorant sometimes and sometimes it is wise not to miss reality. Good luck.