Question about internet connection to streamer

Does the connection (wired or wireless) affect sound quality?
If using CAT 5 cable, is there a difference in “quality” between different cables?  Does the length of cable make a difference?
to avoid dropouts connect with a shielded ethernet cable.....shielded not generic and use a CAT7 ..... sonically I've never compared wired to wireless, IMO wired is always the better choice
This is a controversial subject. Many of us (and science) hold that any decent Ethernet cable will work. After all, audio has a relatively low data rate compared to modern Ethernet. I favor Cat 5e and Cat 6. Blue Jeans Cable tests and certifies their cables to meet specs. I have NEVER had dropouts or other problems using such cables. Nor do I find any appreciable difference between wired and wireless operation, but I can see that might depend on the devices you are using.

Shielded Ethernet cables have become popular with some audiophiles, but the shield can defeat the transformer isolation that otherwise cuts down on noise transmission in Ethernet connections. Is the cable in the walls shielded?

If some audiophiles didn’t find boutique cables worthwhile, there wouldn’t be a market for them. My advice is, try the basic ones first, and put the money you save into music, room acoustics, better gear, or taking your mate to a nice dinner.