I am sorry to hear that. I can understand them wanting to keep you safe, but how unsafe can the front yard be? They can’t shelter you forever. Otherwise, you won’t know how to navigate the world or social situations when you are an adult. Do they expect to keep you under their surveillance for the rest of your life?
Because they are strict, I doubt they will relent, but you can try taking baby steps. Gradually ask for more freedom, and each time, present your request in a way that benefits them. For instance, if you want to go out in the yard, offer to take out the trash. If you want to go to the park, offer to take the dog for a walk, or ask one of them to go with you. That might seem embarrassing, but if they go to the park and see that it’s safe, they may let you go alone.
The same process applies with friends. Try to work within their comfort zone first. Initially, you can ask them if a long time friend can come over. Once you get past that stage, ask to go over to a friend’s house while her parents are home. Then, get their parents’ phone number and give it to your parents. If you have a cell phone, you can also offer to call them when you are on your way over to or back from your friends’ house.
If none of these plans work, there are two other things you can try. First, talk to a sympathetic relative in your extended family, or to a mentor. Perhaps they can argue on your behalf. If that will not work, then speak with your school guidance counselor. S/he might even ask your parents to come in and discuss the issue. They will probably be more open to change if another adult talks to them.
Finally, if all of those solutions fail, then make plans to go to college away from home. You will have to teach yourself how to be independent. I was in a similar situation as you when I was a teenager (though not quite as bad), and in some ways, I’m still behind my peers due to the restrictions placed on me back then. I am having to learn skills that I should’ve learned long ago, and they are more difficult to master at a later age. I was hardly allowed to do anything because they didn’t want me to get hurt. Ironically, they hurt me more by not preparing me for the real world. Hopefully, your parents will learn that lesson before it’s too late.