I strongly recommend that you have a logo created before you actually create your blog. It helps to have your color scheme settled when you go into the actual setup phase. It also helps to have it done so you can launch quickly and not be waiting on a logo to be created.
There are two approaches to having your logo created.
Professionally Done
Some new bloggers will hedge at the idea of paying someone to make a logo, but I think it is the way to go. Just let someone else do it for you. Just send them the links to logos you already like, and BAM, they come up with something AMAZING.
This is my go-to designer for logos on Fiverr.com:
https://www.fiverr.com/idezinefr/design-3-logo-designs
They have always done an amazing job that was done quickly and something I could be proud to put on my blog. It only set me back $50-$80 depending on the project.
DIY
Some new blog owners want to create their own logo, for different reasons. They might not have the money, or they want the experience of making it themselves. I have been in both positions before, sometimes both at the same time.
If you really find yourself in this boat, then I recommend you save yourself some grief and make your logo on Canva.com. I wish this tool was around when I made my very first website back in 2002! Holy cow, it make design work much easier.
Photoshop, and similar tools like GIMP, are fun and great to learns, but have a steep learning curve. You want to get your blog online and creating content, not getting stuck on a logo. Canva will help you do that.
As an example of a DIY logo, I took a free Logo Template on Canva and made one in about 10 minutes:
Logo Template
Finished Logo
Helpful Canva Tutorials
Canva’s Official YouTube Channel
Marley Baird Media – Canva Tutorial
Five Minute Social Media – Canva Tutorial