Wayne39uk, Despite all the potential horror stories, you do need some easy success in your turning. and the reality is I turn all sorts of things and find light weight bowls while fun to make, are disappointing in reality. One of my old tutors once told me if you throw an apple into the bollw and it tips over it isn't a fruit bowl! So the majority of bowls I turn are at least 5mm thick in the wall with 10mm thick bases, so forget the thin walled easy distorted types for now.
Get a moisture meter (about £12)
Get yourself a nice easy piece of wood, something interesting like Yew or Ash that show somewhere between 10% and 15% on the meter.
DONT do an end grain bowl, they can be a problem.
Turn it to about 5mm wall thickness with very sharp tools.
Sand it at slow speed with your fingers not with a pad. if your fingers get warm, so is the wood!
Leave it on the lathe overnight, and Yorkshire grit it the next day (it may have distorted overnight so don't try cutting it again just polish)
Put it in the kitchen for at least 2 days the variable humidity and heat in the kitchen I find is a great settler of newly turned items.
Have a WIN! we all need those.
If you are still having problems post some pictures, and I am sure that help will be offered.
Good luck and happy turning