Both of those projects sound very interesting! I may not be qualified to answer this because I haven’t made it to ISEF, but here’s my advice as one of the few public school students to get an award at the Massachusetts State Science Fair.
When looking for a mentor, try and expand your search beyond state universities. Personally, I got lucky. I started volunteering in a STEM program at my library only to find out that the project coordinator had a background of helping students with the science fair. Her son is the most highly awarded science fair winner in my state! Although she couldn’t help me with the confusing science part of my project, she was a great help for bouncing off ideas, practicing my presentations, and getting my board together, which is a large and often overlooked part of the process. My project was a complete failure (incorrect hypothesis and inconclusive data) and not all that complex, but the presentation makes a huge difference…I saw an insane amount of breathtaking, complex projects that didn’t place. Also, she connected me to a professor at my community college who helped me with the project, gave me a job working in the laboratory this summer, and is letting me use the lab to work on my own project for the next science fair. Like I said, a lot of this was luck, but if you haven’t had success with your state university, reaching out to other people in your community who are passionate about science might bring you some luck too. You could contact your past/current science teachers and see if they can help or know someone, and like I said, I recommend contacting a community college.
However, first I’d recommend doing more research on those two project ideas. Anyone you contact is more likely to help you if you have a better idea of what you want to do. It’s okay to get confused along the process - that’s where mentors come in - but try and get a better understanding of the steps you’d like to take for your project by doing more research so you can be more persuasive as to why someone should mentor you. I found out that at my community college, a large reason I was presented with these opportunities was that I made it clear I could be successful with some guidance. My mentor helps me with my research, and in turn, I’ve brought in good publicity about the college by getting an award, which is just what my mentor was hoping for. If possible, convince them that helping you will be mutually beneficial.
Additionally, as I mentioned earlier, my project was a failure yet I still got an award. If you still can’t find a mentor, just change your topic to something you understand better, and do it really well. Science fair judging rubrics don’t have categories for “incredibly complex” or “will change the world”. The most important thing is convincing the judges that you used the scientific method thoroughly - you don’t need to cure cancer to do well. In my state, there was this insanely complex project about regrowing enamel on people’s teeth (or something like that, I didn’t even understand it) that didn’t place, whereas the grand prize award went to someone whose project measured the PH of snails. I don’t mean to badmouth the snail project, I’m sure it was amazing, but my point is that surface level complexity isn’t what matters.
Best of luck, sorry for such a long response!