There are three general categories of trademarks.
“Word marks” consist solely of letters or numbers and do not contain any other information.
“Stylized marks” consist of a design of some sort including logos, words in specific fonts, or combinations of each.
There also a wide range of “non-traditional marks” including trade dress (product packaging), sounds, colors, scents, motion, and feel.
Your most important trademark is your word mark. When someone other than you mentions your business, this is how they will mention it. The most valuable and reliable expressions of goodwill (third party mentions like word of mouth, media reports) will come without any styling or logos attached to your word mark. Moreover, logos, fonts, colors, come and go with changing tastes, but your word mark needs to last forever, provided you don’t screw it up and have to change it. So, spend a ton of time on coming up with the word portion of trademark. Changing your font, colors, and logo are easy. Changing your name is a disaster.