+1 for Bilt Hamber regular clay and diluted car shampoo with water. Bilt Hamber say you can just use water, but diluted car shampoo (without wax etc) makes the clay glide better, and less likely to marr the paint. The soft clay is even less likely to marr, but harder to clean the paint if the car hasn't been Clayed recently.
The Bilt Hamber bars are 200g, and you only really need 50g chunks at a time. So even if you drop a chunk (and make sure you bin it!) then you have more to carry on with.
Soak the clay in warm water before use so it's easier to fold in the dirty sections. Keep claying until you hear the noise go from rough to silent, if that makes sense? You'll feel it as the bar lifts to muck and goes from feeling rough to feeling smooth. No need to apply too much pressure.
Also get a thin cheap bag and put your hand in it. Run that over section of the paint to feel for when the paint is clean - the bag amplifies the feeling of contamination on the paint.
Buy a spray bottle / use a clean empty one, and constantly spray diluted car shampoo / water mix over the paint as you work. Spray in one hand, clay in the other. I use over a litre of spray for the whole car - keep it really wet and regularly fold the dirty clay to avoid marring.
Keep the clay away from panel gaps and under arches unless you made a real effort to clean them. They can be full of grit.
If you start one day, and continue the next, then I'd rinse the car off again if the car has been left outside, esp with all the work they are doing on the fields at this time of year.
Keep rinsing the shampoo / water mix off of completed sections so it doesn't dry on, then there's less work to do before polishing.
Hope it's looks great!
... Last time I did that half the forum world took offence to doing their own leg work.