Writing is an amazing skill that can both be fun and tedious at the same time. The important thing to remember when it comes to writing is knowing that whatever you write the first time around will not be perfect. In fact, your final product may have been completely transformed from the first few drafts. A few ways to keep the creative juices flowing from your brain onto paper would be to keep a list of writing ideas down. That way, you could keep track of the things you may be more interested in writing about.
Find where your passions and curiosities lie. The topics could be reflective or they could require a lot of research, but always keep an open mind in how you could expand on that writing to go further and deeper into a topic, and also consider how it may affect your audience. When it comes down to writing your first draft, don't overthink it. Many people, including me, think of the first draft like a final draft that is being turned in and graded. I would advise in not spending so much time correcting every little grammar mistake or think too much about formulating sophisticated and complex sentences, over focusing on what ideas you currently have.
The purpose of a rough draft is in its name. It is a "ROUGH" draft, meaning that it is not supposed to be perfect. In fact, it may not even be good.
Begin with writing down whatever comes to mind first, even if it may not make a lot of sense. The idea-vomiting on paper is beneficial because when you come back to revise it, perhaps you have had a more clear idea or even merge some thoughts together that take a direction. From there, you can begin eliminating, elaborating, and organizing your thoughts and ideas when it comes to writing. In the end, make more revisions and elevate your writing. Great writing comes from layers upon layers of revision, but most importantly, it comes from your ideas. So don't be hesitant in writing down anything you have on your mind.