Tom, I've spent a lot of years fishing the lower Niagara River. From shore and in boats. It's a fantastic fishery and it's tough. Lewiston is the main launch on the N.Y. side. The lower Youngstown launch is for very small boats and runs shallow. You definitely need a N.Y. license and you must favor the N.Y. shore side. The middle of the river is the divide. Canada - USA.
If you favor the Canada side you will need a Canada license. Do not push your luck! Years ago both Countries were lenient on enforcing that law....no more!
The Lewiston drift is the main drift to start in a boat as a novice I would still be careful how far up river you go. I don't know what size boat you have but most guys are running deep V's about 18 ft.
Other smaller ones will work but careful is the word. I would not attempt the Devil's Hole area that is farther up river by the power dams.
Lewiston on down river is the majority of boat drift fishing. Some areas produce better but fish can be had throughout the river's drift. You'll need a good trolling motor to keep your drifting even with the current and the shore. The lower area is good fishing down near Fort Niagara. Out in the mouth is the Bar area and that can be excellent when fishable. Look at a map and study some of the area. Once again Canada / N.Y. boundaries.
You really need to go up and survey the area first and see what's going on. Start at Lewiston and check out the launch area and watch the boats and their drifting techniques. I would go up and shore fish the Art Park area first. That way you can see first hand what's going on. Then ride down to Youngstown to the Fort area and check it out. No shore fishing here but you can see the mouth of the river. Shore fishing can be a blast and fighting those big fish in that strong current requires good reliable gear. I use 10lb. line and Med / heavy rods. My reels are Penn 4400's. The river is relentless with snags so be ready. It's the Major League's of river fishing especially from shore. The first time you land a big Steelhead or Lake Trout you will be on a fishing high ! These fish have the whole river to run and jump and a strong current flow that just favors them 100%.
Don't get frustrated it's very challenging but there is nothing comparable in river sport fishing!