As I said I'm new in the tech world and have no knowledge of hardware or software world as not from a technical background. but after a little bit of surfing Linux seems best and safest place to begin with & willing to give 10 hours daily and want to learn. and ill be doing only work like (coding and study purposes only).On coding c++ python PHP etc your mainly working with text files which take up little resource. If you can build yourself a desktop tower that would be handy and you will always get parts. Try and go for 64 bit processor and compatible motherboard. What are your other requirements ?
thanks!For lightweight computing (i.e. no major gaming, video editing, 3D modeling) a single board computer such as the Raspberry Pi might be a good choice. It's cheap: $50 will get you a very usable computer. Some other companies that are aimed at building Linux computers are System76, Tuxedo Computers, Zareason, Pine64, and Purism.