If you haven't done too much conditioning work, I'd start with brisk walking for a half hour to an hour.
After that you can walk for a bit to warm up and then run some short sprints. Start out with 20 yard sprint, maybe 10 of them. Your rest period between sprints will be the walk back to the starting line. Work up slowly to 40 yard sprints. So maybe the next time out you run (9) 20 yards and (1) 30 yards. Next time (8) 20 yards and (2) 30 yards. Once you've hit all at 30 yards, then do (9) 30 yards and (1) 40 yards.
After that you can run those sprints on an incline (hill sprints) or add in more conditioning starters; like performing 10 mountain climbers and immediately get up and sprint 40 yards. One of my favorites is to start with a few burpies and immediately run 40 yards. These are butt-kickers.
My absolute favorite conditioning tool is the Prowler. It's an evil torture device but it's really fun to use. My kids love it too and it's their favorite part of their workouts. I throw on 90 lbs and push it 20-30 yards , twice. Then throw on another 90 lbs (total 180) and repeat. Then another 90 lbs (total 270) and repeat. Then I strip off 90 lbs and repeat. Then strip another 90 lbs and do the last two pushes.
You can get creative with all this conditioning stuff and make it fun. You can use jump ropes, barbell complexes, or even calisthenics. You can mix it up too, do relays with a Prowler, Farmers Walk, and Tire flipping. Load 45 lb plates into the back of a truck, hit a sledgehammer against a tire, and run some hills. Do Power Cleans and then hit a heavy bag for 3 minutes. The possibilities are endless, find something you enjoy and sucks the energy out of you