Hi Clockboy has explained it very well. The K&D tools work well enough in the demonstrations if used properly, I would advise watching a few of these on The tube just to get familiar with its use. The method is that when fitted tio the staking tool and screwed down it supports the arms of the balance on to the stake avoiding distortion. Watch the videos before having a go.
You can also do this...
You buy a pocketwatch movement on Ali:
It's a ETA clone, and practice on this one... It's a bit bigger than a normal movement.
After your done, and when it's still working, you assemble it in a case, and were it proud, your first on build watch!
Hi Should be ok for practise although the calender work is a bit extra for training, as long as its a disposable movement should anthing go wrong. I have enclosed the tech sheet for that model, might help as you re assemble the movement. all the best
3897_Ronda RL 1013, 1113 (RL), 1213, 1313_Smaller.pdf
For a newcomer the skills you'll be needing to pick up are to do with dexterity in handling small parts with tweezers, undoing screws and making sure the screwdriver blade doesn't slip, cleaning parts, reassembly, putting the balance back in place etc. etc.
You don't want to be starting out with expensive movements and so pin-lever designs (like the Ronda 1113) are ideal as they'll introduce you to the makeup of a watch and allow you to practice the above skills and can be picked up pretty inexpensively.
Initially I'd advise getting hold of a working movement. This way you can concentrate on the important dexterity skills and disassembling and reassembling with the aim of the watch still working afterwards! The danger with picking up a non-working movement - especially on cheaper movements with limited shock protection and jewel counts - is that the balance staff can be shot or parts worn which then means you have to get other movements the same for spares or new parts which outweigh the value of the movement.
So in summary I'd say the actual movement you chose is less important than getting something that works already and/or where there is good availability of other 'spares or repairs' movements the same so if something goes wrong you have a parts backup source.