Start off with:

rails g resource comment post:references user:references content:text

Then

rails db:migrate

  resources :posts do
    resources :likes, only: [:create, :destroy]
    resources :comments
  end

In comments controller

class CommentsController < ApplicationController

    def comment_params
        params.require(:comment).permit(:content, :user_id)
    end

    def create
        @post = Post.find(params[:post_id])  # Assuming you have a post object
      
        # Create the comment and associate it with the current_user
        @post.comments.create!(comment_params.merge(user: current_user))
        
        redirect_to @post
      end
end

In Post.rb

has_many :comments

In User.rb

has_many :comments

then create _comment.html.erbf

<div id="<%= dom_id(comment) %>">
	<%= comment.content %>
	<%= time_tag comment.updated_at, "data-local": "time-ago" %>
</div>

_comments.html.erb

<h2> Comments </h2>

<div id="comments">
	<%= render post.comments %>
</div>

<%= render "comments/new", post: post %>

_new.html.erb

<%= form_with model: [ post, Comment.new ] do |f| %>
Your comment: <br>
<%= f.text_area :content, size: "20x5" %> <br>
<%= f.text_field :user_id, value: current_user.id, style: "display: none;" if current_user %>
<%= f.submit %>
<% end %>