We have a 2003 petrol 1.4 Fiesta that has done 57k miles. Recently it has developed an issue where it won't start from cold without a bit of persuasion from the accelerator and then the idling is awful. It's starts off around 1500 rpm but is lumpy and actually sounds like it's about to stall. Once it's warmer it drops to 1000 rpm but still sounds awful like it wants to stall but something keeps it going? It will drive but is bouncy and won't accelerate properly.

Could this be a fault with the throttle sensor and if so, where do I find it and how do I clean it or could this be something else??

I know this does not help much. there is a million things it could be. I think first thing to do it needs to have a fault code reader put on it which might give some clues to what to focus on. Although it does not always tell you with 100% certainty. Fault code readers are cheap on ebay , perhaps you know someone who has one. A garage might charge more to read that fault codes than you can buy a fault code reader for