Advice given to me a long time ago when starting out was “everyone makes mistakes but the measure of a professional is how they fix their mistake/s”.
25fps is the normal PAL system frame rate (Europe etc.) and 30fps is one of the NTSC system frame rates (USA & Japan etc.). I would recommend you select the system frame rate of your country of residence. If your video is for YouTube you can upload in any frame rate.
I found the following video on YouTube that appears to show how to change frame rate in Sony Vegas. https://www.youtube.com/watch?v=BZFVyfrG1uc There are other YouTube videos on the same subject.
