I'm new in this world, please help ;)

[HenryCooper]

You could also get some ideas and inspiration from here:

Windows & keeping bugs out

Hey!! We have windows in our van that slightly pop out letting fresh air at the bottom. We are wanting to keep the van doors open/windows just before bed as it is very hot in Arizona but are finding the van filled with bugs (obviously) how does everybody fix this issue? We are thinking about putting up mosquito screens but wanted advice first! Thanks Jordan

And here’s an alternative to curtains.

VAN LIFE: Custom Reflectix Window Coverings for Insulation & Privacy