I think OP already gave up from the cost, but to bring the topic back to "how to become vtuber" a bit, the cost/preparations to become a vtuber are :
1.the art for base avartar
2.rigging artist - the more variations you want to be able to move, the more time/cost it takes
3.Live2D program
4.facecam hardware
5.video editing softwares
6.voice changer program (optional)(do note that if you want to change from a man->girl's voice, you'd also need voice practices, as the program could only get you about halfway there)
Naturally, anything you can do yourself will cut money spent but cost time, and anything you hire others will save time but cost money + risks (finished product end up not how you want, don't get any product at all/delivered way past deadline, etc.), but OP's spec of "red orb with glowing eyes" should be realatively cheap, since it wouldn't have a mouth to do the rigging for.
As for how to join us down here in the Hololive hole, I guess it depends on what you like. Personally I got in through a sub clip where they do a prank call collab on their friends and I found them entertaining enough to look for more + start the Youtube algorithm working (it's the 4 Marines and a Aqua one), so you could hang out in the communities and check out some clips you found interesting, or try to seek them out and put some of their live archives on the background while you do something else and maybe pop in when you heard them do something interesting/make weird sounds.
For that "background sounds" route, heres a few example :
Singing streams. They're idols (yes,really), so most of them have a few out every once in a while
Inugami Korone (the brown dog) 's oldschool games (she can be very tenacious and go on for hours, 10 hours streams are common)
Tsunomaki Watame (sheep) 's Minecraft building projects (she's currently making houses sort-of modeled after her Hololive friends)
Usada Pekora (rabbit) 's Fallguy/any games you'd expected to hear player's crying and begging to get a "win" (she often get smug while winning and desperately pleading when losing, often within seconds from each other)
Or you could check out their 3D debut streams, which are 1 hour clips of them in 3D models and entertaining their fans, which could give you a quick glimps of how their characters and fans are like.