I used to go to a gym vs I used to went to a gym

Some examples from the web:

• I used to go to film school in Ukraine.
• I used to go to a lot of parties.
• I used to go to Princeton whenever I could.
• Before the uprising, I used to go to Bethlehem often.
• So, I used to go to this school choir.
• I used to go to church on Sunday.
• I used to go to church on Sundays.
• I used to go to the Criterion with Michael.
• Kyle and I used to go to this thing together.
• I used to go to confession at Saint Cecilia's.
• I used to go - to meet girls.
• Every Tuesday, I used to go to the Shree Siddhivinayak temple.
• I used to go to the planetarium every single evening.
• I used to go to school with your son, Scott.
• Someone I used to go to for my own intel.
• Man, I used to go to summer camp down there.
• I used to go to night clubs in Ginza three times a week.
• I used to go to the Anubis Spa.
• You know, I used to go to the factory a lot.
• I used to go to this school when I was a kid.

Some examples from the web:

• I used to love to box, but I don't bother with a gym membership anymore.
• I used to wait until you went to bed.
• I used to win awards for volunteer work. I went to Guatemala and fixed cleft palates.
• I used to think she went to work... to get away from me.
• I used to live up here a long time ago, and I saw them when I went to camp.
• I used to tell myself that every day he went to work.
• Carla and I used to tell each other news every night, before we went to sleep.
• I used to hear it at my aunts' house before I went to sleep.
• I used to say it every night before I went to sleep.
• I used to make my dad say it to me every morning before he went to work.
• I used to take a shortcut every day when I went to work at Dr Dixon's house.
• I used to be studious and, every time I went near the gym, - I got beat up.
• Do you know, when you were little, I used to watch you sleep every night before I went to bed, just for a few minutes.
• On Sundays, Ellen and I used to go get FroYo and then we went to see a picture at the Ziegfeld.
• I used to be here, on the teams, you know, back in the nineties, before I got out and went to the seminary.
• Do you know when you were little, I used to watch you sleep every night before I went to bed, Just for a few minutes.
• I used to go to Carlo Bini School, Then I went to La Marmora, and then to Pistelli.
• We - I used to - we went to high school together And I talked to him on the phone.
• I remember going in there, man... and I used to go to a Catholic church, and I went to a Methodist church... I went to all them other churches, man, but then I went to this black church... in Oakland.
• I used to see you on the tram. I thought you only went to the French Quarter.