If you had to start all over again in this day and age

On streaming, tech wise it’s really painless. Of course you need internet access. Ethernet cables access to your modem is best, but some streamers like the Bluesound will also work over WiFi. 
The three streamer dacs that I currently use are the aforementioned Bluesound in my budget office system, Cambridge 851n in my secondary system and Teac NT-505 in my main system. 
There are big sound quality performance increases at each of those steps. The Teac is still relatively affordable at $2k and sounds amazing, but it requires Ethernet (no WiFi ). 
The Bluesound is the easiest to use and has the best user interface app of the three, but it’s dac is wanting IMO. Ymmv

Please excuse my dumbness but this is all new to me. So I need a streamer. I either have to get one with wifi or wired directly to my modem right?
Now I attach this streamer to my cd player dac with what type connectives? ("digital in" means hdmi?)

Why does the streamer have to be quality if it seems to be only a conduit? I just saw a streamer with dac for $23,000.

Also, I have to pay a monthly fee to join up with a provider like Apple music? What’s "tidal"?

My word. My questions are like "what spark plugs should I use" Sorry.

A streamer gets your music from your wifi router (modem) to your DAC or you can combine both functions in a streamer/DAC. You can connect to your wifi router wirelessly (wifi) or wired (ethernet cable, i.e. Cat 6, Cat 7, etc.).

Digital inputs and outputs will be labelled as such on the component. There are several types of digital cable that you can use to connect a streamer (digital out) to a DAC (digital in).

If you want to read up on this topic, there are a number of very recent threads about New to Streaming, Newbee Question About Streaming, etc. Just do a search of the forums for Streaming and sort by date.

If you read those and are still puzzled, you’re like me. The easiest way to learn about streaming is to buy a Bluesound Node 2i (a Streamer/DAC with a digital out so you can connect it to a separate DAC, if you want to) for $550 list price. It’s really easy to set up and the BluOs app you use to control the streamer is very user friendly. It will sound good enough for starters and you can get a separate DAC if you want better sound once you decide whether you like streaming or not. Eventually, you can spend as much as you want (or have) for better streaming gear if you feel that’s necessary.

Tidal, Qobuz and Amazon Music are streaming services which cost $15 - $20 a month. I think they all offer a free one month trial so you can decide which one you prefer or if you like streaming at all. I like streaming, other people like physical media. You can do both, using streaming to find music you really like, then buying a physical copy.

Ok, thanks Tom.
I'll check the forum out as you advise. Just one more quicky though: Say I stream a song into streamer. Does it get stored in there so I can play it back at any point or do I always have to use a streaming network for play back?