@joshuawheat; I don’t own a manual car now (I have my first DSG) but I drove manuals for well over 40 years. I can‘t say I ever consciously considered what the engine rpm’s were - or should be - when pulling away from standstill. From my experience, it’s all about getting the balance right between applying pressure to the accelerator pedal and releasing the clutch pedal, and using just enough rpm‘s to move off smoothly and not stall the engine - not using excessive rpm’s where you’re over-revving the engine and wasting fuel. More often than not, you can find that no two cars behave the same when pulling away from rest - even cars of the same make and model. I’ve had courtesy cars from my dealer that were the same make / model as the car I owned at the time and the clutch action / rpms required to move off from rest was different in the courtesy car compared to my car. I’d also say that the amount of rpms required to pull away smoothly from rest in a GTI may be different when compared to, say, a Golf 1.5 R-Line, so responses from forum members might not be relevant to your particular model of Golf if they don’t own the same model as you do.
You can hear and feel through natural instinct if you need to use a little more or less engine rpm’s to achieve a smooth start from rest. IMHO there’s no ‘one size fits all’ answer to your question, as the amount of engine rpm’s required when moving off will vary depending on circumstances; e.g. when pulling away on a upward facing slope or incline in a car without driver aids such as hill hold, you may need to use more engine rpm’s than you would when pulling away on a level surface or a downward facing slope.
I’d suggest you find somewhere quiet away from other traffic (in an empty car park perhaps) where you can get used to your specific car‘s characteristics when moving away from rest, and getting the balance right between accelerator and clutch pedal usage. Alternatively, if you feel there’s an issue with your specific car, then consider getting a tech from your dealership to test your car with you as passenger so you can see how they pull away from standstill and how many rpm’s they’re using.