I have a few questions on my misdemeanor charges and what the effects of them are?

Im 17 years old and I live in Wisconsin. I have two obstruction of justice, misdemeanor charges. I was wondering if my record will be cleared when I turn 18. I was also wondering if these charges are keeping me from getting a job, on applications it asks if i have committed a crime but i dont know if i should check yes or no and list them. Im afraid if I check yes it will be an automatic rejection. If I no then they might run a background check and see that im lying. I plan on going to the army after high school and then off to college, will these charges effect that too? What are the effects that these charges have on me?