Thank you so much for your question!
How many research journals, on average, do participants refer to?
There certainly is not a set amount of journals that one should refer too. I'm sure it differs from category to category, but it never hurts to have as many sources as possible!
Are there any sites on the internet that are of help when gathering research journals? A lot of sites tend to require payment for access to the research papers.
Your best bet would be the PubMed database
. Although many journals require payment for access, there is a decent amount of journals you can access free of charge. Google Scholar has many options as well.
Any tips for the layout, font etc for preparing my project report?
I would refer to ISEF's official page for tips on layout and presentation.
There are some good tips on here that include how to prepare your paper. As for the report, I'm not sure there is a length requirement, but I would check the website to be sure.
Hope this helps!