There will be 4 - off "strong enough" points under the car to use a trolley jack with a spreader pad on it, look for the 4 - off round hardish plastic bungs - not soft rubberish bungs - they tend to have a countersink groove on the surface, that is where you can permanently fit Audi TT MK1 Jacking Point protectors, the front ones are inboard of the sill and towards the front of the car form the official jacking point, the rear ones are again inboard of the sill and towards the rear of the car. For the axle stands you will need to make up or buy slotted blocks with HD rubber on the top - and use under the official jacking points.
If you are going to keep this car for a while, the Audi TT jacking pads are for handy, well at least for me as I have 2 trolley jacks that have small lifting cup that fits these jacking pads exactly, they let you grab a trolley jack look underneath and quickly place the jack's cup below 2 of these points and lift one side up at a time, then slip in a couple of axle stands and repeat on the other side.
These 4 - off strongish points are only there for factory use when moving the bodies around, but as soon as Audi started using them to ease lifting the TT, lots of people used them on cars up to the Golf etc weight/size range. I've hd absolutely no issues with using them since they became available or on my radar, since maybe 2004 onwards, I had to buy a new set for my wife's 2015 Polo when we bought it as I had left it too late to start trying to remove them from her old 2002 Polo.
Edit:- I've spent a bit of time making up suitable axle/jack stand padded adapters for both my cars, each one slightly different as the body profile at or near the jacking points are different on different models, but in each case I've made a point of only using the vertical folded seam as a locator and kept the weight of my cars mainly on the flat area behind the sill and some on the front of the sill, though the area supporting the front or outer area is really only being used to improve stability should any of the other 3 supporting points want to induce any tilting. I'm just trying to keep things safe while also protecting my cars while working under them. My load spreaders are slightly longer than the jacking points. I stopped lifting my cars at a single point years ago as I don't like stressing the frame welds any more than they see in normal daily use.