Looking for audio amplifier circuit using 2SC1050 transistor
Part 1 - Use 2N3055 to learn audio amplifier
Update 2020sep24hkt14:47
How nice to see @ocrdu updating our crowded answer with the following critical jigsaw puzzle piece!


Update and Errata 2020sep24hkt1322 - The above title before this update had a typo - 2N3005 SCR should read 2N3005 NPN transistor.  Many thanks to @Andrew Morton for pointing out my severe careless mistake.

2SC1050 is not that popular, therefore you find it difficult to google things for it.
Instead you may like to try 2N3055, which can do what 2SC1050 can, and is perhaps 100 times more popular, so you can find tons of tutorials on it.
The following is an example of a couple of YouTube tutorials to get you started.
(1) DIY Audio Amplifier with 2N3055 Transistor - cbz 2019nov23

Part 2 Small Power audio amplifiers
2SC2050 or 2N3055 are for big power audio amp.  For smaller power, you might like to consider the following.
(a) DIY PAM8610 Digital HiFi Power Amplifier Board 15W + 15W Small Power Mini Audio Amp Kit DC12V - US$8
(b) LM386 Low Voltage Audio Power Amplifier - TI

References
(1) Whatever Happened To The Electronics Hobbyist?
(2) eevBLAB #2 - Are Electronics Hobbyists Useless? (YouTube)
(3) EEVblog #874 - World's Oldest Electronics Hobbyist! (YouTube)
(4) The Decline of Hobby Electronics? (YouTube)
(5) An Electronics Workspace for a Design Engineer - elektormagazine
(6) The 10 Best Raspberry Pi Stores Available in the Market
(7) Inside a 12W LED module (12:26 Schematic) - BigClive
(8) 2SC1050 Based Power Amplifier
(9) JohnAudioTech Videos