The opening is the most important part of your PS. You need to tell the tutors why you wanna do the course. What made you want to do the course. It's better that you don't start with your first paragraph as it needs to the greatest and best of your PS. So my advice is to do your other paragraphs and when you finish then you will have already know what to write on there. Hope that helps.
No problem. Also find examples so you know how and what to write in your PS. One site I found helpful is https://www.studential.com/personal-statement-examples This site has many PS and you can look at examples of PS of your chosen Course.