It is better to create new environment with new name ($newenv):conda create -n $newenv tensorflow
Then by using anaconda navigator under environment tab you can find newenv in the middle column.
By clicking on the play button open terminal and type: activate tensorflow
Then install tensorflow inside the newenv by typing: pip install tensorflow
Now you have tensorflow inside the new environment so then install jupyter by typing: pip install jupyter notebook
Then just simply type: jupyter notebook
to run the jupyter notebook.
Inside of the jupyter notebook type: import tensorflow as tf
To test the the tf you can use THIS LINK