I look forward to starting up my own business as I am from a business background so business fascinates me a lot.
Well, one suggestion is to not repeat the word business over and over like this. The thing to do is focus on what you really want to do. Saying "business" does not mean much. Describe the kind of business you want to be involved in and what strategies you might use. If you don't have any strategies in mind, you must not be the kind of student who has a vision for the future, and your essay will reflect that. The plan you describe will be superficial.
Similarly, if you don't have any ideas about why you want to be in the UK, your ideas will be superficial. you mention "exposure, opportunities, challenges, rewards and satisfaction," but these are just abstract concepts that are not particularly linked to the UK.
Maybe your business plan is intended for enactment in the UK. Google: how to write a business plan.
You wrote a beautiful sentence about the importance about imagining the future. I think you should read some books while you are imagining, so that your imagining can turn into planning. For example, do some imagining while you read Good to Great by Collins, and you will start to get deep insight into business... insight that even adults do not have.
You are ready now to make a real plan and enact it. It'll change, but come up with a tentative plan for now and describe it in these little essays! I think you already know what is missing; it's the plan!!! :-)