The priorities you list in your 1:1 meeting and the level of details depend very much on your function and activity as well as the level of information you wish to share with your manager.

If you don't know where to start, simply list the most important things you wish to accomplish or that are on the top of your agenda until next 1:1 meeting.

Next time you see your manager, ask him if he/she is happy with the level of details that you gave him/her.