Situation: I just hit 40K km and want to replace the chain and sprockets.

I want to change my gearing a bit to improve highway fuel efficiency.

Problem: I can not find a reliable source for the stock sprocket sizes. Or what size chain to get to compensate.

I don't understand the differences between brands or other alphanumeric combinations with the parts. Example, "EK 525 SRX2 Quadra-X8 Ring Chain"

I also think I should get a chain tool in case I get the wrong size chain, but have no idea what to look for.

What I already know: I want to go up a tooth in the front for my gearing change. The stock chain is 110 links. I need everything to be the same 5XX number. I live in Canada.

Questions:

What are the differences between chains and sprocket brands/numbers?

Would going up two teeth in the front be too much?

Would a one tooth change require a larger chain?

What chain tool should I get?

What are the chances I will screw this up if I do it myself(I'm mechanically inclined and used to do most of the work to my own car.)?

Sorry if this is a bad post and thanks for any help you give me.

Edit: missed an asterisk, added bike info, fixed typo.