The ~best~ starting point for a "beginner" is the streamer one has on hand.
Bottom line, do not overlook and underestimate and undervalue what you already have.
What follows is basic, generalized and summarized for "beginner" purposes.
A mobile phone is the most versatile streaming platform one owns. It is configured for accessing and delivering a wide swath of streaming services WITH EASE.
The ’limitation’ is around the output port, should one choose to go wired. There are many products that allow for the phone’s internal DAC to be bypassed. They also deliver a quality stream to your DAC or Pre, or headphones, depending on the product you choose to use. Cost of these devices and adaptor cables is low.
One’s laptop or tablet can serve the same role. The laptop (tablet to a lesser extent) offers more flexibility in output ports. Laptops can run a number of software options to optimize streaming, sonic performance, and with enhanced user interfaces.
All three can be used wireless and via networked connections and network control. A major benefit of going wireless is the (by default) isolation of the source device.
A TV, a Roku, Apple TV, Amazon Fire, Chromecast or similar device also serve as effective audio streamers. A limitation here is with TOSLINK, which will have an upper limit for frequency/bit rates... transmitter, cable, and receiver dependent. User interface is easy enough though can and will fall short (device dependant).
Your phone or tablet or laptop will most likely serve as your User Interface, even if one is using a standalone server/streamer/network player. In other words, your phone, laptop and tablet are already in and part of the mix. Further, one can simply cast from your laptop, tablet and phone should you own an appropriate receiving device.
The enhanced ability to isolate digital streaming products, apply filters, etc. etc. has moved forward to a degree that makes a phone, a laptop, a tablet etc. a very effective starting point. And when executed properly, capable of delivering high quality sonics. This did not use to be the case.