Type of kit needed is dependant on the water you will fish...
Natural livebaits such as maggots , worms , smaller fish can usually be fished anywhere using a run of the mill 8ft telescopic 'spinning rod' ,along with a standard reel.
Anything between 2ib and 6ib breaking strain is good for game fishing for trout and others.
Float fishing - anything buoyant that will indicate that a fish is on , can be used.
If the water is generally shallow ( 2ft or less ) and moving at a medium pace , I would use a simple method of a few lead weights on the line and a small hook , and let the bait move across the bottom of the water with the current.
If the water is shallow but slow moving - I would use a small float with the lead weights this time , distance between float and bait - should be just on the bottom and no more.
If the water is generally deeper ( 4ft or more ) and moving fast I would use a metal spinner such as the 'devon minnow' or the 'toby'.
If the water is generally deeper but slow moving then you are free to use whichever method you can , you have enough depth to use a spinner , and the water is going slow enough to use the float method also.
On lakes / lochs / tarns I would generally use the method more suited to the water depth where you are , shallow , just use a 'fixed line' , deeper - try spinning or float fishing.
Fly fishing is another thing altogether and is NOT an easy method of catching fish.
You must know which flies are getting eaten by the fish ( look around , check what flies are in any cobwebs
and choose your nearest matching fly. )
You have 3 methods , dry fly , wet fly and nymphing.
All are different , all take a long time to master.
The kit req'd for each method is also different , diff flies , diff line , diff technique.