Is it possible to build a humanoid at home without prior knowledge
There are a few tutorials on DIY humanoid robot. Here is one you can follow:
Before that, you can practice something easier like this. Just to increase your expertise:
Hi @skatz60 and welcome to the forum!
If you don’t want to build your humanoid robot from scratch, you can buy already made robots from RobotShop: humanoid robot - RobotShop USA
I hope this helps.
A kit is probably a good place to start unless you have good build and coding experience - make sure it includes code. If you want to start from scratch and learn 3d printing, mechanical design, low level microcontroller coding, maybe high level python coding, you don’t know what a PID controller is (I didn’t used to know) etc then it’s a very steep learning curve. Or just follow one of the instructables. If you already know how to 3d print, control servos, understand or quickly learn PID controls, maybe how to integrate an IMU, then from scratch or from a basic design is possible.