logo: image vs text

Do you have guidance regarding a logo design? I am taking massive action regarding promoting my email list and newsletter (I coach nurses who are feeling overwhelmed with work or life and want to support them during our current medical crisis). I currently do not have a logo and do not want to use this as an excuse to not move forward.

1. Is it just a matter of preference if a logo has a symbol/logomark vs just text ie: business name or is there some benefit of one over the other?
2. Is it better to send out my materials without a logo or pick something and “rebrand” in the future if need be? By better I mean is there a business advantage of one over the other.
3. I saw someone comment on Brooke’s recommendation about a design competition on 99designs: where did Brooke talk about this? I am familiar with that website 🙂

As always, thanks for your help!