Do I need plans to renovate my home?

This is technically possible but it is not recommended.

In a case of a small job, ie. flooring replacement, you might not need a set of plans. Even in this case, the communication between you and your contractor must still be at a high level. See the video about expectations.

The set of blueprints/plans will give your contractor the ability to price the job accurately. If you do not have a set of plans, the price of the project is arbitrary and the chance of it changing in the process is very high.