You might face some difficulties in deciding the colour scheme, the theme and so what not. My suggestion is you should go through lot of blogs and find out what style you like most. Then you can start working on your own blog.
If you feel sad or down when the command you typed in not working, take a rest. Don't get angry or quit. Take some rest time, shut down the laptop and try to distract yourself with other things. After you feel like you are ready to start again, then do as you wish. Always read the instruction properly so you won't do mistakes.
I wish you all the best for designing your own blog! Cheers!