Well I am somewhat of a new tech myself. I'm 17 years old and about 2 to 3 years ago my uncle ( a computer tech) started me off learning the components of a computer so I could start fixing it myself instead of shipping it to him across the country everytime it broke down. What I did to start off was open the case so you can see all the parts, and learn to identify where each component is located and what it does (ie. locating the motherboard, PSU, GPU). If you have your motherboard's manual, that will help you even further to see how the CPU and RAM are inserted to the board, the different settings that you can adjust in the BIOS. That's a good start as far as the basics go. Once you feel comfortable knowing where everything is and how to properly insert new components, I would by yourself some new RAM and swap out the old one. Mess with the DRAM settings in the BIOS to overclock a bit. Then try replacing a CPU. That is a bit more tricky to do considering you have to be extreamly careful with the chip, otherwise you are screwed. When handling a motherboard always remember to be gentle but firm, and whatever you do don't slip and slightly hit the motherboard with a screwdriver. Trust me... not a good idea.
Thats essentially how I got started, if you have any questions or comments let me know. I'm sure other techs who reply will have different methods considering about 98% of them are far more experienced than me.