The seller needs to give notice to the tenants with the amount of lead time specified in the leases. If it's not specified, or there are no leases, then you need to follow the state's landlord/tenant handbook on how much notice you should give before an inspection of the home.
Assuming you really want a 14 space park that far away, then you'll want to probably compress all of your on-site diligence into one visit. On something that small, I would think 2-3 days is plenty of time if you schedule everything properly before hand. After you get the on-site stuff is done, then you'll schedule the phase 1 and survey.