How do you create a fully customizable main menu?

I have a brief idea on how to do this, It's just complicated and I'm not too professional at scripting. I have a simple loading screen that fades in and out after 20 seconds, then I have a model scene where I have a part as a camera. I have set the local camera, but I need help with the gui and character customization. If anyone knows a good tutorial on this, please lmk. If anyone is professional at guis and scripting, please lmk. I am also willing to pay someone that could help me with this gui. I'm willing to pay lots of robux / money if someone could create me a really nice looking gui (no boxy frames, smooth animations, fading in and out frames, etc.) Thanks!