1.5 to 2 lbs weekly is healthy weight loss. Combo of less calories and more cardio will help you acheive that outcome. Add some strength or resistance training to enhance the cardio benefit and tone your muscles.
Make a couple of realistic and specific goals that include exercise and healthy eating this week. After rate your success as a percentage. If your under 50% success keep or tweak your goal
If over 50% success then keep or increase your weekly goal.
Keep it specific..measurable...action oriented...realistic and on a timeline. SMART!
You have 2 and a half months, thats reasonable time to lose 15~20 pounds