Talk to your coach,
Your coach might help you with the money part if thats it. If its that your mom is being stubborn, again talk to your coach because your coach has probably been in this situatuon before. As for outside sources that help your cause
Also Email College coaches if its a college camp your thinking abou attending because they again can probably help and most of the time are willing to help and definately have been there done that. Also, you dont have to go to camp as I'll DM you some places to get the evidence from camps. If your parents dont/wont let you go to debate camp, you can also just meet with coaches/other students and even your partner once he/she gets done from debate camp! You can find a lot of the things that help you in terms of speaking online and about the only thing you cant do is the seminars (if youve never been to debate camp before its the most boring part).