Hi team. I am new to this digital logic and I would like to learn how to build my own PC ( hardware and OS ) . what do you suggest I have to follow and watch to be able to design it ?

That’s quite a lofty goal. I found this to be helpful https://www.nand2tetris.org/

thanks

You can a look at MiST/MISTer which tries to implement old computers on FPGA boards. There is also oa486 implementation of 468 PC which has a MiSTer core