If your entity creation process has "serious" implications for your users, and especially if it may involve them taking actions outside your app (booking a ticket somewhere, buying something and retrieving a tracking number), you may want to print a summary page where they get key information about how you identify the entity they've created and the offline actions they can perform related to it.
If on the other hand entity creation is a mundane task, and all entities can be browsed from within your app at a later stage / do not normally require the user to remember or take note of any specific thing, then you can simply move to the "next" page and add a visible notification that indicates success / error / passes basic information about the task. See for instance Bootstrap's alerts. I personally use those with strong enough green/red colors (+ clear symbolic icons for color-blind users), so users can understand when an error occurred¹ or be notified that the entity submission process worked.
(if you end up using a light enough form of feedback that doesn't take an entire page)
What is the one action that your user is very likely to do after creating a new entity? Taking them to the place where they can perform that action could be a good idea. If they can do several things (e.g. further edit the entity, or create a new one, or list all entities they've created and manage their moderation progress), then you could either:
- use different "submit" buttons (only if very few actions, else there's a cognitive overload associated with it when submitting the form, which can stress novice users as they may be worried to click the wrong button and lose their progress)
- take users to a "landing" page where they can get the different options they might need
- A note on errors: it's really bad to display an error after the user has done all the inputing, and it's better to catch errors on the fly and notify users about them locally, where they occur. This being said, you can still have bugs in your application or network/client issues which might cause a form submission to fail and require showing such an error. Post-hoc error notifications can be suitable for such unexpected, unrecoverable errors.