I'm a teenager myself so I relate to your question completely. I used to struggle with modest dressing a lot. I was never one to wear revealing clothes or things that showed off my body too much. Just sweatpants and tank tops was my go to, and sometimes is now. But at one point I started to realize that I was wearing certain things because they would make certain parts of my body look good. When choosing clothes to wear, you shouldn't ask whether this type or that type of clothing is allowed, but instead you should ask yourself, "How are these clothes making me feel? What are my motivations for wearing them?" If you wear a tank top and decide that you're wearing it because it's very hot on that particular day, I don't see why you shouldn't. As long as your motivations are to please God, then I think that you're on the right path. Including in that list though is that your first thought shouldn't be, "Will this tempt someone?" If you've dressed in a certain way and know that it will please God, then in the same hand it shouldn't tempt someone. The sad reality is that young women are objectified and sexually assaulted regardless of what they wear at times. Some men are also tempted by girls who wear the baggiest of clothes! So make sure that your foremost priority of the clothing you pick is to please God and represent Him through your clothing, and essentially your whole being. God bless and lots of love to you!