This is going to be a trial and error for you. Some people will suggest finishing each workout with a rowing session. Other, like myself, like to lift one day and do conditioning the next. Personally, when I finish my lifting session with cardio I either half ass it or skip it entirely. I also found that I recover better, by doing conditioning on a separate day, plus my conditioning workouts are better.
So my program looks like this. Monday, Wednesday, and Friday I strength train. Right now, I don't have much time to workout, so I pick 3 exercises, a squat, press, and pull and follow the 5x5 protocol. If I had more time I would be doing 5-6 exercises. On Tuesday and Thursday I do conditioning. These workouts are brief, usually only lasting 4-15 minutes long. I finish these workouts with extra stretching, foam rolling, and some sort of core training. On Saturday and/or Sunday I will do 60-90 minutes of easy cardio, such as hiking, walking, or biking.
The second method is to lift 3-4 days and finish each workout with an intense rowing session. Some people like this method, because their off days are truly off days.
Try both for 4 weeks and pick one.