Please do not take what I am about to say as a criticism of Walmart Community Church, because I honestly know very little about it.
Just a word of wisdom from a shepherd: In the midst of the excitement and energy of a big church with a great band, be sure to make the distinction between fervent worship based on good theology and fleshly worship that springs from emotionalism. You cannot see the hearts of the people around you, but you can see the fruit.
Good churches do not shy away from calling people to biblical change. Fluffy churches just want a lot of people. The two often look the same on the surface, but I know you are discerning enough to tell the difference.
Whether the setting is big or small, contemporary or traditional, pay attention to the efforts a church exerts to make disciples (as opposed to "win souls" or "be a social club"). If the regular public services are primarily given over to evangelism, you are going to find a church full of people who think theology is irrelevant to life. If the primary purpose of a church is making lost people comfortable, something of great value is going to be compromised. Then you know you are in the wrong church.
Accountability is important. Find a church that will not let you hide (and there are large churches that hold people accountable, as well as small churches that care little how you live).
As long as I am holding you accountable (very pastoral of me, don’t you think?), be careful that you do not fall into the snare of a romantic relationship during this time of major life changes. So many young ladies away from dads and brothers like the security of a guy, but it can be a real spiritual distraction. I have encouraged my boys to observe girls from a distance—starting in work and Christian service settings. Observing from a distance, you really get to know if a guy loves Christ more than female attention. Make sure he would choose Jesus over you any day.