This is actually a pretty common question, but the truth is that chords alone cannot tell you what strum pattern to use! Chords have to do directly with your left hand, and strumming has to do with your right. So having the chords in front of you will only give you one piece of the puzzle.
If you have a good chart, it will identify what time signature to use. This gives instructions for your right hand. 4/4 is referred to as "common time" and is by far the most popular. Tap your foot to a song on the radio, and you will see that every 4 taps, the chord changes. You are tapping out 4 quarter notes. There are of course other times signatures, but if you learn what to do with a 4/4 time signature, you will have the knowledge to tackle 80% of songs.
Now, once you've identified the time signature, you must either play a 4/4 strum pattern or craft one that is within these parameters. If you're completely new to time signatures, don't worry! The whole process of what those numbers mean is covered in the Rhythm Basics lesson in the Beginner Series. It's lesson #9. The following lesson is on how to play a common 4/4 strum pattern.
If you're ready to tackle some other 4/4 strum patterns or learn some more strum patterns for different time signatures, then check out the Essentials Series. There are a good handful covered to prepare you for all sorts of rhythm.