Is there a way to make a Press E to sit localscript when near a object?

Yes, you will need to know 3 things to create this. Magnitude which is basically the length of a Vector. The method Sit(humanoid) for a Seat Instance. You will also need to know how InputBegan event works from UserInputService.

First, put all your Seats in a folder that's in workspace. Insert a local script into StarterGui(or wherever local scripts run). Let's start by defining a few variables.

-- // Services \\ --
local UserInputService = game:GetService("UserInputService")
local Players = game:GetService("Players")

-- // Variables \\ --
local Player = Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait() -- // If character isn't loaded wait till its added

local Seats = workspace.Seats -- // Seats folder where all the seats 
local RANGE = 8 -- // How close you have to be to a seat in order to press E.

Next, we are going to need to make one function which is going to be called GetClosestSeat(). We are going to loop through all of the Seats and check the magnitude of the (Seat.Position-Character.HumanoidRootPart.Position). If the magnitude is less than or equal to the range, we will insert the Seat along with the magnitude in a table. Why a table? Well, what if two seats are in range. We want to sit in the closest seat, so we use a table to collect all the seats in range and then sort them according to how close they are.

-- // Services \\ --
local UserInputService = game:GetService("UserInputService")
local Players = game:GetService("Players")

-- // Variables \\ --
local Player = Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait() -- // If character isn't loaded wait till its added
local Humanoid = Character:WaitForChild("Humanoid")

local Seats = workspace.Seats -- // Seats folder where all the seats 
local RANGE = 8 -- // How close you have to be to a seat in order to press E.

-- // Functions \\ --
local function GetClosestSeat()
	local SeatsInRange = {}
	for _,seat in pairs(Seats:GetChildren()) do
		local mag = (seat.Position-Character.HumanoidRootPart.Position).Magnitude
		if mag <= RANGE then
			table.insert(SeatsInRange, {Seat = seat, Mag = mag}) -- // Insert into the table because the seat is in range.
		end
	end

	if #SeatsInRange > 0 then -- // If there are seats near the character.
		table.sort(SeatsInRange, function(a,b) -- // Sort the table, so the closest seat is the first index of the table.
			a.Mag < b.Mag 
		end)
		return SeatsInRange[1].Seat -- // Return the closest seat after sorting.
	else
		return nil -- // Return nil if no seats are close.
	end
end

Now, we are going to need to use InputBegan from UserInputService and call the function to see if there is a seat in range and sit on it.

-- // Services \\ --
local UserInputService = game:GetService("UserInputService")
local Players = game:GetService("Players")

-- // Variables \\ --
local Player = Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait() -- // If character isn't loaded wait till its added
local Humanoid = Character:WaitForChild("Humanoid")

local Seats = workspace.Seats -- // Seats folder where all the seats 
local RANGE = 8 -- // How close you have to be to a seat in order to press E.

-- // Functions \\ --
local function GetClosestSeat()
	local SeatsInRange = {}
	for _,seat in pairs(Seats:GetChildren()) do
		local mag = (seat.Position-Character.HumanoidRootPart.Position).Magnitude
		if mag <= RANGE then
			table.insert(SeatsInRange, {Seat = seat, Mag = mag}) -- // Insert into the table because the seat is in range.
		end
	end

	if #SeatsInRange > 0 then -- // If there are seats near the character.
		table.sort(SeatsInRange, function(a,b) -- // Sort the table, so the closest seat is the first index of the table.
			a.Mag < b.Mag 
		end)
		return SeatsInRange[1].Seat -- // Return the closest seat after sorting.
	else
		return nil -- // Return nil if no seats are close.
	end
end

UserInputService.InputBegan:Connect(function(Input, GameProcessed)
	if GameProcessed then return end -- // If player is typing in chat(or other gameProcessed events) then we won't run the code.

	if Input.KeyCode == Enum.KeyCode.E and Humanoid.Sit == false then -- // If E key is pressed and the humanoid is not currently sitting. 
		local ClosestSeat = GetClosestSeat()
		if ClosestSeat ~= nil then -- // If there is a close seat.
			ClosestSeat:Sit(Humanoid)
		end
	end
end)

I hope this helped you. I am in school right now and don't have time to test this, but looking at it, it should work. If you have any problems, feel free to ask. I would appreciate if you accept this answer if it worked out for you. Thanks!