OpenAI Gym Jupyter Notebook NameError Traceback (most recent call last)

Question

I wanted to start with Cartpole. Whenever I try to test any of my variable like enviroment_name

NameError Traceback (most recent call last) Cell In[7], line 1 ----> 1 enviroment_name
NameError: name 'enviroment_name' is not defined.

Likewise, if I try env.action_space.sample(), I get

NameError Traceback (most recent call last) Cell In[12], line 1 ----> 1 env.action_space.sample() 
NameError: name 'env' is not defined.` And so on.

Please guide me.

Also, I want to understand this first, before moving to Network Attack Simulator (NASim) which also similar OpenAI gym.

I was expecting an output on each of my defined variable. Before moving further. TIA