Hi Idris,
I work in Brixham, lovely this time of year. What type of fish are you looking for?
Some day tickets available on the Upper teign for brown trout for about £12.50 I think - see
Upper Teign Fishing Association.
Also Fishing on the Upper Dart and Duchy of Cornwall (wooded) stretch for about £20.
Sea trout fishing mainly Lower Teign, some on Upper Teign also.
These are probably nearest, a good resource for all types of fishing in the southwest here:
Get Hooked | Get Hooked Guide to fishing in Cornwall, Devon, Somerset, Dorset, Wiltshire, Hampshire, South Gloucestershire
Also take a look at
www.swlakestrust.org.uk for reservoir fishing (some free) for some more family friendly areas, although there's a nice pub (!) and grassy area at fingle bridge on the upper teign.
Hope this helps!!