Just adding a few more details for context:

The area isn’t perfectly level all the way to the edges, but we’ve already installed French drains and intentional drainage, so we’re not worried about pooling or water flow. Because of that, we don’t plan to do major regrading—just enough to prep for gravel.

Also, we’re planning to use a pea gravel binder/glue to help lock the gravel in place and keep things tidy and low-maintenance over time.

Thanks again for all the advice—really appreciate any insight, especially around how to work around tree roots without harming the tree and other considerations concerning the yard not being completely level!

How well this is going to work depends on location. Where I am, pea gravel is very much a PITA. In a drier area, where lack of water does the heavy lifting of weed control, it can work. In a humid area, grass is hard to beat for low maintenance.

I put a fire pit in a couple years ago - however, it was part of a large patio installation (including a covered patio area). I know people who have used a paver kit to build a fire pit (some of them look really nice). Of course, there are all different types of fire pits ($-$$) - not sure what your budget is for this project.

I also know someone who put one in exactly the way you are planning to do. They did the correct prep work in order to have weed control (weed barrier) under the pea gravel. I have pea gravel in the front yard of my lake house (I don't want to have to mow when we go down there!) - it's not that difficult to keep the weeds under control (and I live in an area where it is humid during the summer!).

This next one is how we did our fire pit at the lake house - it's made with the same pavers as the patio/fire pit at my full time home (Pavestone I think) - and the fire pit looks very similar to the one that we have at home. It took us just a few hours to get the area ready (had pea gravel delivered and spread out).

This fire pit kit below was less money - but some people had issues with putting it together correctly. The pieces are cut very precisely apparently = must be placed in a specific order. There were many people who had no issues with building it.

The person I know used large square concrete pavers and left room between them to put pea gravel. FYI - there is stuff that they sprayed on the pea gravel that helps make it stay in between the concrete pavers instead of being kicked all over the place).

Here is a cute one where they added a course of edge pavers (that's not the correct name - I am blanking right now!) + made some easy wood poles inside barrels with concrete in order to string lights around everything. I didn't want to add any lights around mine at the lake because we don't need to attract any extra mosquitos/bugs!

Your yard is crying out for more greenery. I'd put in some shrubs by the fence, not gravel.

A few pix of our fire pit. Natural gas. Brick edging. Removed grass and about 4” of earth - put down weed-block before the gravel. Merrimack river-rock.

This really seems like a slope. How are you going to put seating here around the pit without people being off kilter?

Pea gravel by itself is a poor choice for walking and putting furniture on. You could put in washed #1 stone and then random papers over that, with wide joints to let water through.

What are your local ordinances/laws about firepits? Many municipalities have them. Some may allow an open wood burning pit, some might have restrictions because of the proximity to wooden fence, buildings, trees. And might only allow for something like a tabletop burner for ambiance, or a freestanding caged wood burner. Do you have a spigot and hose on that side of the house for the sake of fire safety?

Be aware that even if you do glue the gravel into place, it will still need regular cleaning for weeds. Stone mulch can trap seeds and sprout weeds. Glued gravel also can trap dirt that does not dislodge with maintenance. And since you are planning on it being a traffic area, you may need to apply the glue and maintain it more often than you might if it was a non-traffic area.

How are you planning on dealing with seating on a slope?

Many people have slopes in their yards that have to be dealt with for various things. For example, my backyard slopes from right to the left side of my house. We had a large paver patio installed - on the left side is two retaining walls that were constructed in order to make a flat area for the patio. We use the area in the retaining walls for landscaping.

You can do the same thing (but on a smaller scale) for your fire pit.

This yard below has a pretty steep slope = a large retaining wall was required.

There are YouTube videos on how to deal with making a fire pit on a slope.

Here is a "before" photo of a backyard with a slope that was posted on Reddit.:

Here is the "after" photo - 21 days later - with a new fire pit:

We had to get a permit to build our covered portion of our patio. We did not have to obtain a .permit to add a fire pit - and I live in a city near a large metropolitan area (not a rural area). My city tends to be very restrictive and goes a bit "overboard" with ordinances and required permits - so, if my city didn't require one, it's likely that yours won't (but you still need to check).

Some visual