Trouble installing Ruby on Rails in Windows - no localhost - ruby-on-rails

Question

I'm new to Ruby / Ruby on Rails, and coding in general. I've gone through the Ruby course on Code Academy, and now I'm about to do Ruby on Rails, but was hoping to actually make something as I go through the course, to help with my understanding of it.
I've tried using Windows Command Prompt and Git Bash to make a new rails app. It seems to run fine when I type rails new MySite. It creates a folder in the right place. This also seems to run bundle install on it's own, and if I type bundle install, it says Could not locate Gemfile. But when I type rails server, it doesn't give me a localhost at all. It just says:
Usage:
rails new APP_PATH [options]
Options:
[--skip-namespace], [--no-skip-namespace] # Skip namespace (affects only isolated engines)
[--skip-collision-check], [--no-skip-collision-check] # Skip collision check
-r, [--ruby=PATH] # Path to the Ruby binary of your choice
# Default: C:/Ruby27-x64/bin/ruby.exe
-m, [--template=TEMPLATE] # Path to some application template (can be a filesystem path or URL)
-d, [--database=DATABASE] # Preconfigure for selected database (options: mysql/postgresql/sqlite3/oracle/sqlserver/jdbcmysql/jdbcsqlite3/jdbcpostgresql/jdbc)
# Default: sqlite3
[--skip-gemfile], [--no-skip-gemfile] # Don't create a Gemfile
-G, [--skip-git], [--no-skip-git] # Skip .gitignore file
[--skip-keeps], [--no-skip-keeps] # Skip source control .keep files
-M, [--skip-action-mailer], [--no-skip-action-mailer] # Skip Action Mailer files
[--skip-action-mailbox], [--no-skip-action-mailbox] # Skip Action Mailbox gem
[--skip-action-text], [--no-skip-action-text] # Skip Action Text gem
-O, [--skip-active-record], [--no-skip-active-record] # Skip Active Record files
[--skip-active-job], [--no-skip-active-job] # Skip Active Job
[--skip-active-storage], [--no-skip-active-storage] # Skip Active Storage files
-P, [--skip-puma], [--no-skip-puma] # Skip Puma related files
-C, [--skip-action-cable], [--no-skip-action-cable] # Skip Action Cable files
-S, [--skip-sprockets], [--no-skip-sprockets] # Skip Sprockets files
[--skip-spring], [--no-skip-spring] # Don't install Spring application preloader
[--skip-listen], [--no-skip-listen] # Don't generate configuration that depends on the listen gem
-J, [--skip-javascript], [--no-skip-javascript] # Skip JavaScript files
[--skip-turbolinks], [--no-skip-turbolinks] # Skip turbolinks gem
[--skip-jbuilder], [--no-skip-jbuilder] # Skip jbuilder gem
-T, [--skip-test], [--no-skip-test] # Skip test files
[--skip-system-test], [--no-skip-system-test] # Skip system test files
[--skip-bootsnap], [--no-skip-bootsnap] # Skip bootsnap gem
[--dev], [--no-dev] # Set up the application with Gemfile pointing to your Rails checkout
[--edge], [--no-edge] # Set up the application with Gemfile pointing to Rails repository
[--master], [--no-master] # Set up the application with Gemfile pointing to Rails repository main branch
[--rc=RC] # Path to file containing extra configuration options for rails command
[--no-rc], [--no-no-rc] # Skip loading of extra configuration options from .railsrc file
[--api], [--no-api] # Preconfigure smaller stack for API only apps
[--minimal], [--no-minimal] # Preconfigure a minimal rails app
-B, [--skip-bundle], [--no-skip-bundle] # Don't run bundle install
--webpacker, [--webpack=WEBPACK] # Preconfigure Webpack with a particular framework (options: react, vue, angular, elm, stimulus)
[--skip-webpack-install], [--no-skip-webpack-install] # Don't run Webpack install
Runtime options:
-f, [--force] # Overwrite files that already exist
-p, [--pretend], [--no-pretend] # Run but do not make any changes
-q, [--quiet], [--no-quiet] # Suppress status output
-s, [--skip], [--no-skip] # Skip files that already exist
Rails options:
-h, [--help], [--no-help] # Show this help message and quit
-v, [--version], [--no-version] # Show Rails version number and quit
Description:
The 'rails new' command creates a new Rails application with a default
directory structure and configuration at the path you specify.
You can specify extra command-line arguments to be used every time
'rails new' runs in the .railsrc configuration file in your home directory,
or in $XDG_CONFIG_HOME/rails/railsrc if XDG_CONFIG_HOME is set.
Note that the arguments specified in the .railsrc file don't affect the
defaults values shown above in this help message.
Example:
rails new ~/Code/Ruby/weblog
This generates a skeletal Rails installation in ~/Code/Ruby/weblog.
I've also tried installing Ubuntu (20.04 LTS), as I've read that it can help with rails issues, but I can't get that to work either - I can't even set up a username and password, as it says
The specified network name is no longer available
I have:
Windows 10, Version 2004 (OS Build 19041.1052)
Rails 6.1.4
Ruby 2.7.3p183
Yarn 1.22.10
Node v14.17.2
I'm sorry if I've given too much / not the right info - not sure what would be helpful. I spent most of today and yesterday googling this and trying to figure it out, but I've hit a wall. Any help would be really appreciated