What opportunities are there to gain experience in Project management planning in your companies ?

First of all, a company has to have projects culture (i.e. performs projects often), you can ask to be enrolled in a project. For me, I started as a team member in a project, and have had a formal training in project management, then had the chance to re-plan the project activities as my workstream was a busy one, and then had good feedback, and gained a reputation within the company, and started the project management career. Hope this helps.

The ones that you create! It's up to you where you position yourself.