Skating questions from a newbie

So...I'm completely new to hockey, grew up in the South where hockey didn't really exist. Never really even watched a game before last October, went to a couple games with a friend and have since I've been to quite a few NHL games and am really developing a love for the sport. I'm interested in learning to play and possibly join in some pickup games or a beginner level league, I think it would be a ton of fun. Have thought about ice and inline and right now I'm leaning towards inline as around here it seems to be a bit more beginner-friendly but ice hockey isn't out of the question yet either. I'm 27 and 225lbs, not really a natural athlete but am strong, tough, and determined-- but still I hope I'm not getting into something over my head.

I've done a little bit of learning from some friends playing street hockey but figure step 1 is getting to be a decent skater. I bought some Bauer XR3 skates and have been getting used to skating mostly just skating around the house and in the garage to get a feel for it and such. We are going to hit up one of the outdoor rinks in a week or two. My balance is ok and I can turn fairly well in both directions, not great at stopping yet but I am improving. Will be working on backwards this week. Only been at it for about a week, so I'm happy considering I've barely skated at all before this.

Yesterday I ventured out to some sidewalks at a park around here and quickly made a fool of myself...even the SLIGHTEST uphill/downhill threw me off...

So here's my questions....
How much different is skating outside on streets/sidewalks compared to a rink? I feel comfortable on a flat surface but was completely lost once I came across any sort of incline.

Will outdoor wheels help me on technique? I have 76A wheels on my skates now. I know the indoor wheels will wear out faster but do they also have a different feel when used on outdoor surfaces?

Maybe I need to spend more time at a rink rather than outside...I just thought that any skating I do will help be get better.

Any other advice?