I assume because you mentioned Kaplan then it will cost $$$. I wouldn't pay a dime to those guys, but maybe you are rich. Otherwise, you can do it all for free.
If it is the essay part you are worried about then find people you know to help. I assume you have a health profession committee that wrote a letter for you? Ask them to review your essays too. I asked several old professors, my dentist and even found my old Comp I teacher. They helped me by reading my essay and correcting things. Before I submitted I asked two friends to read it just to make sure it was in my voice and reflected who I am.
If you haven't done a lot of extracurricular stuff then it will show no matter how you pad it. One guy on here mentioned how during the interviews they really chatted him up about his past experiences. The last thing you want to do is pad your apps with random stuff and then show up and not be able to talk about it. Just be honest and list what you have done.
If you have any other questions ask on here. I dont know about other peoples experiences, but I find that the people on here are pretty honest and spot on when it comes to answering stuff.