Just change the path of the location where you have anaconda installed, then you can run anaconda-navigator and from there you can launch jupyter notebook or you can just run it straight away using jupyter-notebook. Also you like the error says it is recommended to run it as normal user since you will be using it like any other normal application.
raman@raman:~$ source /opt/anaconda/bin/activate root
bash: /opt/anaconda/bin/activate: No such file or directory
raman@raman:~$ cd /home/raman/Downloads
raman@raman:~/Downloads$ source /opt/anaconda/bin/activate root
bash: /opt/anaconda/bin/activate: No such file or directory
raman@raman:~/Downloads$ cd /home/raman/Downloads/Anaconda3-2020.07-Linux-x86_64.sh
bash: cd: /home/raman/Downloads/Anaconda3-2020.07-Linux-x86_64.sh: Not a directory
raman@raman:~/Downloads$ source /opt/anaconda/bin/activate root
bash: /opt/anaconda/bin/activate: No such file or directory
raman@raman:~/Downloads$
You installed anaconda3 under /root/anaconda3, your normal user doesn't have the permissions to access the directory structure there. Move anaconda3 to /opt/anaconda3, then your normal user should be able to access it.
As root user: mv /root/anaconda3 /opt
This way it will be available to all users, and otherwise you could just move it somewhere in /home/raman directory structure. Or you could just run the installer als your normal user and it would ask you if the default installation path is okay with you which will be somewhere in the directory structure of the user executing the installer.
raman@raman:~$ source /opt/anaconda3/bin/activate root
bash: /root/anaconda3/bin/conda: Permission denied
raman@raman:~$ su
Password:
root@raman:/home/raman# source /opt/anaconda3/bin/activate root
bash: /root/anaconda3/bin/conda: No such file or directory
root@raman:/home/raman# source /opt/anaconda3/bin/activate opt
bash: /root/anaconda3/bin/conda: No such file or directory
root@raman:/home/raman#
other outputs
raman@raman:~$ jupyter-notebook
bash: jupyter-notebook: command not found
raman@raman:~$ su
Password:
root@raman:/home/raman# jupyter-notebook
bash: jupyter-notebook: command not found
root@raman:/home/raman#
In this file: /opt/anaconda/etc/profile.d/cond.sh, make sure these look like this:
export CONDA_EXE='/opt/anaconda3/bin/conda'
export CONDA_PYTHON_EXE='/opt/anaconda3/bin/python'
Your file probably still has /root/anaconda3 there.
raman@raman:~$ source /opt/anaconda3/bin/activate root
bash: /opt/anaconda3/bin/conda: /root/anaconda3/bin/python: bad interpreter: Permission denied
raman@raman:~$ su
Password:
root@raman:/home/raman# source /opt/anaconda3/bin/activate root
bash: /opt/anaconda3/bin/conda: /root/anaconda3/bin/python: bad interpreter: No such file or directory
root@raman:/home/raman# jupyter-notebook
bash: /opt/anaconda3/bin/jupyter-notebook: /root/anaconda3/bin/python: bad interpreter: No such file or directory
root@raman:/home/raman#
What does your /root/.bashrc look like? Otherwise you can just remove /opt/anaconda3, and then run the anaconda installer as normal user and it will install it in a location that you should be able to run it from.