1. You can go ahead with the report;
To go ahead = proceed
2. I look forward to meeting you next week;
To look forward to = be excited about the future
3. We need to sort the bills out before the first of the month;
To sort something out = organize, resolve a problem
4. Stick to the deadline;
To stick to something = continue doing something, limit yourself to one particular thing
5. We will have to work out the total cost;
To work something out = make a calculation