Yes you will need time for your dog. I have two small energetic terriers. They need at least 2 walks in a day once in the morning and once at night. Then they need some time fetching the ball, and long after I am tired they are still ready to go.

Remember most likely your dog will be sleeping all day saving up energy just for you. And it usually is alot of energy.

Also dogs take time to train. If you have never owned dogs before invest time in a training school. Be aware of what dog will fit your personality and life style. Some dogs and owners just do not fit together. Or some breeds are just not for new dog owners.

Gary