Unable to install nodejs and npm correctly?

I want to install nodejs its npm manager but when i try to execute its commands throwing the following error...I tried to install in different methods whatever i found in google and after installing also some packages from it are missing.

The following packages have unmet dependencies:
npm : Depends: nodejs but it is not going to be installed
   Depends: node-abbrev (>= 1.0.4) but it is not going to be installed
   Depends: node-ansi (>= 0.3.0-2) but it is not going to be installed
   Depends: node-ansi-color-table but it is not going to be installed
   Depends: node-archy but it is not going to be installed
   Depends: node-block-stream but it is not going to be installed
   Depends: node-fstream (>= 0.1.22) but it is not going to be installed
   Depends: node-fstream-ignore but it is not going to be installed
   Depends: node-github-url-from-git but it is not going to be installed
   Depends: node-glob (>= 3.1.21) but it is not going to be installed
   Depends: node-graceful-fs (>= 2.0.0) but it is not going to be installed
   Depends: node-inherits but it is not going to be installed
   Depends: node-ini (>= 1.1.0) but it is not going to be installed
   Depends: node-lockfile but it is not going to be installed
   Depends: node-lru-cache (>= 2.3.0) but it is not going to be installed
   Depends: node-minimatch (>= 0.2.11) but it is not going to be installed
   Depends: node-mkdirp (>= 0.3.3) but it is not going to be installed
   Depends: node-gyp (>= 0.10.9) but it is not going to be installed
   Depends: node-nopt (>= 3.0.1) but it is not going to be installed
   Depends: node-npmlog but it is not going to be installed
   Depends: node-once but it is not going to be installed
   Depends: node-osenv but it is not going to be installed
   Depends: node-read but it is not going to be installed
   Depends: node-read-package-json (>= 1.1.0) but it is not going to be installed
   Depends: node-request (>= 2.25.0) but it is not going to be installed
   Depends: node-retry but it is not going to be installed
   Depends: node-rimraf (>= 2.2.2) but it is not going to be installed
   Depends: node-semver (>= 2.1.0) but it is not going to be installed
   Depends: node-sha but it is not going to be installed
   Depends: node-slide but it is not going to be installed
   Depends: node-tar (>= 0.1.18) but it is not going to be installed
   Depends: node-underscore but it is not going to be installed
   Depends: node-which but it is not going to be installed

Someone please help with proper way of installation.

Solution 1:

Node.js package is available in two releases: LTS release and the current release. You can install any version you want. I am installing LTS version for this answer.

1. Add Node.js PPA

You will need curl to download the script, so first, install curl by typing sudo apt install curl in the terminal.

Once, curl is installed successfully, run the command to download and install the installer.

curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -

2. Install nodejs

Now, run the below command install node on and Ubuntu using apt. This commmand will also install npm with nodejs. It will also install dependencies.

sudo apt install nodejs

Note: To check the version of node run the command

node -v 

To check the version of npm run the command

npm -v