The best fishing is fly fishing:
Rod size determines species for a starter something in the 6-7 or 8 range. The fight in wicked on a fly rod the small fish feel like monsters.
Rod length --> I like 8-10ft rods but that entirely abut your comfort. St croix for quality I have nothing bad to say about my rod.
Line type --> sinking or floating. I say floating and just add an extra long tippet. and get some right decent backing cause some of the big boys will strip the fly line clean and you'll be fighting with your backing. Long tippet is required the longer the better.
Flies --> match the hatch, first thing I do when I get to a river is wade in find a nice size stone, turn it over and check out what nymphs are around.
Look for something called GYmp it used to be what I used, rub that on your dry flies to keep they on top else eventually they sink. Margarine works too if your all out but messy.
Then most important part:
Casting, you need to learn all the proper casting techniques because as you get deeper and deeper into those back woods trying to cast a fly roll cast will become something you rely on.
Personal Tip: I got this one way back when I was buying waders, The guy would NOT sell me chest waders as a punk teenager anyways. His reasoning was too many people drown in chest waders as they just can't get out fast enough. The hip wader come off right easy. Maybe he was right I've had a few times taking that next step and it's like your sliding down some cliff under water no traction hahahaha.