Can Sprint fix my iPhone 4S?

My iPhone just recently started blurring out the Wi-Fi setting and now I can't use Wi-Fi. I checked online using my phones serial number and my one year warranty is still good. I was wondering if I could take my phone back to sprint who I bought it from in the first place and was wondering if they could replace or fix it? If so do I need to bring my mom or something? Because she pays for my bill or can I just do it myself?

Yes. Go to Sprint and bring your mom. They may either give you a new phone or take your phone and fix it up. If there are any fees that needs to be paid which probably won't happen since you still have warranty, you will need your mom to pay them.

My iPhone just recently started blurring out the Wi-Fi setting and now I can't use Wi-Fi. I checked online using my phones serial number and my one year warranty is still good. I was wondering if I could take my phone back to sprint who I bought it from in the first place and was wondering if they could replace or fix it?
-----------Per Apple/Wireless Carrier contract, absolutely no wireless carrier can troubleshoot hardware/software/Firmware issues/errors, other than rebooting and a itunes restoral. Wireless carriers can only troubleshoot network issues. Apple troubleshoots the rest. This is why everyone at ATT/Verizon/Sprint/Tmobile is reffered to Apple for warranty issues, software/hardware issues, etc… So, you can go to Sprint… All the little agent is going to do is walk behind the counter/desk… And call Apple… LMAO! Go on… See if i'm telling the truth. LMAO

If so do I need to bring my mom or something?
-------- the account holder (whoever pays the monthly bill) needs to be present

Because she pays for my bill or can I just do it myself?
-------- if the bill is in your name and you pay the bill on your own, then do it yourself… Other than that, attempt to do it yourself without account holder permission constitutes as wireless fraud, a felony in the USA…