Your situation
Before there is an offer, there is time
This is the easiest stage to be in and the one most owners waste. Nothing is due, nothing is decided, and everything you do now makes the later stages go better.
Why this stage matters
The appraisal has not been written yet
Once an appraisal exists, everything afterwards is a response to it. Before it exists, you can influence what goes into it, and that is worth more than any argument made later.
The specific opportunity is the inspection. An appraiser visiting your property sees what is visible. They do not see the septic field, the drainage that runs under the strip being taken, the second access used only in winter, the way delivery vehicles turn, or the land you bought next door and farm as one unit. If nobody tells them, none of it is in the valuation.
Write down what the appraiser needs to know, and hand it over. It is the cheapest thing you can do in this entire process and it routinely changes the number.
Questions to ask
What to ask the agency now
What exactly do you need
Area, location, and whether it is fee title, a permanent easement or a temporary one. These are very different things.
What will be built
Plans and cross sections. What ends up next to what you keep matters more than the area taken.
Is there federal funding
It determines which appraisal standards and which relocation rules apply.
When do you need it
Construction programmes drive agency urgency, and knowing the schedule is useful.
Who values it
Whether the appraisal is in house or contracted, and whether you may attend the inspection.
What about the rest of my land
Raise the remainder early, particularly if what is left would be hard to use.
Questions at this stage
Should I get my own appraisal now
Usually not yet. Wait for theirs, read the reasoning, and then decide. An appraisal review costs less and tells you whether a full independent valuation is worth it.
Can I say no
Generally not to the taking itself. You can and should negotiate the amount and the extent, and on easements the terms are more negotiable than most owners realise.
Should I hire a lawyer already
If the sums are substantial, or part of your property is being taken, an early conversation is worth it. For a small clean acquisition, waiting for the offer is reasonable.
They want me to sign a right of entry
Read it. Entry for survey is often permitted by statute anyway, so signing may grant more than it needs to.
Find the site that answers your question properly
This is a starting point. The detailed answers live on the sites built for each question, and on the site for your state.