There are two tasks to complete:
1. To create a logo from a logo you have researched. You can only use the logo as an example. The logo you create must have no copy/paste.
The logo size is 1280px x 860 px. This size allows for a practical down size for a letterhead, or business card, or full size for a poster.
2. To create an A4 poster, using either your own creation or one that you have researched and decided to copy. No copy/paste is permitted and it must all be your own work. the poster size is A4, vertical 210mm x 297mm.
In both tasks, do your research carefully. Look at what's already out there and create your own masterpieces. Do not over extend yourself and keep within your comfort zone.
Use the many tutorials on Illustrator, as well as the toolbox linked pages.
Many of the Illustrator tools need to have the object selected before moving further on. The selection and direct section tools are the way to go.
Remember that colouring and using gradients are better Photoshopped. The files are compatible and Photoshop is much easier than Illustrator's tools for these options.