My daughters Barina Help

1995 Barina SB Automatic (opel)
Heres the problem:

After the car has warmed up and she stops the engine
sometimes after starting again and changing from park to reverse or drive the engine cuts out.It may cut out again a few times or may not.What I have noticed is that the engine seems to rev a little higher
sometimes after starting.If she leaves it idling till the engine slows it nearly always does not cut out.
Any ideas?
Thanks in advance

vacuum leak

Yeah, sounds like vacuum to me also.

So how would I go about checking the vaccuum?

if you've never worked on a car before its best to let a professional to do it. But basically you listen for hissing under the hood, but if its small you might not be able to hear it.