My first time playing tennis

I went to play tennis with two of my friends today and it was the most embarrass moment in my life. It's my first time playing tennis, I really don't know how to play tennis. My friend taught me how to serve and receive the ball, but I kept missing the ball. At first I thought tennis is easy, but I realize it's not easy at all, it requires a lot of strength and I don't have any of that. It seems that I can never hit the ball over the net, and I kept missing the ball, so I have to go pick up a lot of those balls. I'm so tired just by running back and forth picking up balls. I almost gave up, but my friends encourage me to give it another chance, so I tried and after 2 hours later, I finally learned how to serve the ball. I was so excited, but the downfall is that I could never hit the ball back, but I'm thinking of practicing more often now, so I hope I could improve. This was a great experience for me.