You have several resources at your disposal... the first place would be at an FAA Sectional (paper or online) to determine what Airspace it is and if there are any Airspace restrictions (
TFR, Special Use, Military etc). If you're good to go then you just need to look at a sUAS ap to make sure there's no National Park Service Land because you can't fly "from/on" NPS land
(but you can legally fly OVER it but that's a whole other topic).
Next you need to look locally for any Land Use restrictions in play and lastly you just look around the area and make sure it's not "marked" as no Drone/sUAS operations allowed. Make sure the land you're flying from, physically standing on, parking on etc is not private property and if it is you'll want to make sure it's ok with the property owner.
So you need to research:
- Federal restrictions (Airspace, TFR, etc)
- State/local Gvt Restrictions (Land Use Laws)
- Visible Signage at location
- Property Ownership