There are recommendations (sorry, my phone won't let me find the link) on the gov UK website somewhere.
You must be careful with phrases like "fresh" or "free range" as there are very specific details that must be true to use them. Ours say "eggs from free ranging hens" which avoids this distinction.
I believe you must put something on that has a use by date, which must be no more than 28 days from day of lay (we say "eat within three weeks" and ensure no eggs are left out for more than 7 days from lay) and although you should not allow them to get hot or cold before selling to avoid disrupting the "bloom", you should advise refrigeration to customers.
That's just off the top of my head, check the gov UK recommendations for all the legal wording.