Yes, most definitely. Otherwise your playing will sound terrible no matter what you play. Here are a few examples of tuners you can use.
Here on the right you’ll see the old pitch pipe type of tuner. Players would blow into the pipe and then tune the guitar string by ear to the pitch they wanted.
ELECTRIC CLIP ON TUNER
Next is an example of a electric clip on tuner. These tuners are clipped onto the headstock of the guitar. You play a string and the tuner listens to the string and tells you how out of tune your guitar is.
GUITAR TUNER APPS
Last but not least is the guitar tuner app. This is probably the most convenient tuner because you don’t need to buy a real tuner and they’re free to download. If you have a smart phone you can download one here. I recommend the GUITAR TUNA app. Click the links below depending on the type of phone you have.