In preview, whilst editing, everything about my project is fine however after it has been rendered, the video is sped up to be 3 or 4 seconds faster and the audio is also slightly more higher pitched and I have no idea what's causing it nor how to fix it.
It's not too big a deal but it's proving incredibly frustrating and annoying and I hope someone can help me fix this. I have CC2017 and this is a recent problem, my AE never used to do this before until maybe a couple months ago, I tried ignoring it but it just got too frustrating for me.
These are my composition setting as for export settings, i'm not sure what you mean...I should probably also mention I know next to nothing about AE, just simple things and things I've learnt off Youtube
It sounds like you're composition time base (Frames Per Second) is not being matched in your render settings. For instance, if you're animating at 24p and then export a 60 fps video file you're effectively speeding it up twice as fast.
Try setting your work area to just a second or two of your program and exporting it out as a test to see if you can match the frame rates. If that test is a success then move forward with exporting the whole video.
Keep in mind too that not all playback software apps can deal with all frame rates nor can all formats. An animated gif for instance set to 12fps may play back at 30fps in the Quicktime player, running way too fast. Depending on keyframes set this can get even stranger.