You will also hear, "We have a lot of ground to cover." https://idioms.thefreedictionary.com/cover+a+lot+of+ground To review a large amount of information or discuss many topics. We need to cover a lot of ground in American History before the exam date. Fig. to deal with much information and many facts. The history lecture covered a lot of ground today.

It would depend upon the situation and the person saying it, but essentially means there is a lot of information either to be discussed or taught/presented. Example scenarios: - Classroom: teacher says "we have a lot to cover this morning", to mean a significant amount of the study material will be taught this morning. - Work: manager/boss in a meeting says "we have a lot to cover..." means there will be a lot of information presented to you, so listen attentively and do not ask questions! Haha

that means you have a lot of work to do