Audiovox CDM-9900

Thanks I got this phone just two days ago and i love it!!!!! 😁 , the last one in a verizon store just 15 min form where I live. Im new here, I want some ringtones I followed the tutorial exactly except for the downloads from Walmart because they charge you 88 per song (plus the 25 to Vzn) and I dont know if I m going to find what i want in Walmart. I have sent mid files of 84 and 80 k I dont think they are two large are they? and I have this message: "unsupported content type application/octet-stream myringer.mid " Ive done everything except that I used my mp3 songs not the ones from walmart. Some help please
thank you in advance 🙂