No, you cannot delete a user in Salesforce, once their account has been created and they have been shared the ownership of certain records, they couldn’t be deleted from Salesforce. But there is another way, and that is you could remove their license, or deactivate them to prevent them from accessing your systems or new records.
Excited to break into marketing team with skill in Salesforce? Enroll in a Salesforce training course, from a reputed e-learning company like Intellipaat and get yourself trained in it by learning through instructor-led training and performing guided projects. Also, have a look at our YouTube video on Salesforce Tutorial for Beginners from our domain-experts.