To better understand the ServiceNow Prerequisites you have understand ITIL concepts.
Click on the below link for ITIL Concept
You can create your own Service-Now instances (10 Mins)
Kindly find the below screenshots of instance creation for your reference.
1. Click on register on the right hand corner side at the top as shown below.
2. Fill the fields as below and click on submit button.
3. Login with username and password and it will redirect to the page to enter country, pin-code and click on submit
4. After that it will redirect to the page below.
5. Go to manage>Instance
6. Click on request instance and select the version(Jakarta).
7. click on the url and login to the instance with the credentials which has been mentioned at the bottom of the page and reset your password accordingly.
8. After instance creation go through below e-learnings which gives you the overall view of service-now navigations and concepts
Click on the below link for html, css, Java script
html, css, Java script