E&O Article that has a downloadable PDF of what E&O info needed: http://www.indiewire.com/2015/08/fimmaker-must-read-attorney-take-on-err...
Other than that man just go and do it. The more red tape added to a film, the less cool filmmaking becomes. Permits and permission are gross, just hide logos/labels (or make your own brands a la QT with Red Apples) and just go.
If you have crew, assign one person to be the look out. Wear t-shirts/hoodies from your local college and if a cop tries to give you trouble, say its for a school project. Only a punk ass cop will try to take your footage, but in my experience, they'll just tell you to kick rocks and get out of here. If this park you're filming in is a national park, just be cautious of the warning/trail signs.
Since its a feature film, watermark your finalized script and email it to yourself via file attachment, then leave it unread (star it if you use gmail for quick reference). Then the next step would be submitting a PDF copy of the script to the Writers Guild of America (WGA). You'll end up getting a diploma-esque form in the mail a few weeks later from WGA saying your script has been processed. Then boom, you'll have proof of copyright.
Other than that just go film the damn thing. Show no mercy. Its hard as fuck making a short film and damn near impossible to make a feature. If you're already about to press record, do that shit and see you at the film festivals.
Best of luck!
Grab any camera you have access to film. Write what you have available to you. Yes, even if it means shooting on your cell phone if you don't have a camcorder or DSLR camera. Challenge the norm of filmmaking, don't follow it.
Don't know professional or even upcoming theater actors to be in your movie? Have your friends/relatives/siblings be in it and make your characters mute/silent. Or better yet, have it star yourself. Think of new ways around a roadblock, instead of turning around and going home.
Don't get caught up with these dick-measuring contests about camera, gear, etc. Those people will make you feel intimidated to go on IMDB to just watch a trailer, let alone help you write and shoot your films. Avoid reading those posts like the plague, they'll only slow you down.
Don't have mics for good audio? Yes you do, use your voice notes app on your iPhone (Or android equivalent). Just watch for fly overs (Nearby airplanes flying over you ruining your audio, car horns, etc).
Above all, just go out and do it. Movies are stories. Not what audio gear you used, not lens comparisons, not what cameras you used or even what actors you got. Its a story. Don't let anyone complicate or convince you otherwise.