Just my 2 pence
if the wheel is a few years old then the nipples tend to corrode / stick to the spokes. During adjustment the spokes twist rather than the nipples tightening the spokes....... either the spokes break or the nipples make jumping sounds when tightening and are not making smooth adjustments..... not the easiest thing.
On this occasion I'd get the wheels sorted by a local LBS and practice on new / newer wheels
The above is true also, however this afternoon just before I posted, someone was moaning about their wheel and it was really no tension at all, but I had a look and they did tighten nicely, looked an oldish wheel, but if it was made with a little oil on the threads they can be ok to work with. Most of the spokes you could tighten with your fingers!
My first attempts back in the day were terrible, if the spokes are older non stainless, they will probably be like above, i.e. terrible and just twist, depends on the state of them.