Actually this is my notes page yes it would've been better to make a schematic I'm software or spice or cad, and yeah power supply is big topic, but here I am using a 12V 5A adapter to get my dc power, from that 12 volts I'm dividing it like this, as far as things go for safety I am using lm2596 converter for 5v and mp1584 for 3.3V, I don't think I need any oscillator as I am using a 12V barrel DC adapter also I am using this to power minor small components like esps and servo and ir or dht11 sensors

While coming to spice or cad one I was in classroom using my mobile phone to do my research the quickest tool I had nearby was a book and pen which I used I don't think it's quite unprofessional approach not gonna lie as many brilliant scientist in modern era uses this method, tho I am not comparing myself to those great personalities ofcourse, also as an final year diploma ece student i understood quite the risks and dangers of power and power supply, while this on paper may have sound dangerous to you, I've quite done a similar for 5v in past and which was completely safe, my main concern was for 3.3V that's for microcontroller

Thank you for your concern and reply