The most common search phrase for this site is "How to be a Gothi/Gothia" (with its various spellings). It is also a fairly common contact question. Since it seems to be such a popular thing to ask, a more formal answer is in order. Though most don't like my usual answer.
The first thing to know is that there is no formal Gothi profession in Asatru. It's not something where you get a degree or certificate and you are suddenly an ordained Gothi. The Gothi is the person who leads an Asatru ceremony. It is usually a respected elder in the group. If you are a solitary practitioner, then you are the Gothi when you hold your ceremonies. That's all there is to it.
Note: I keep using the word Gothi even though that is technically the male version. If I keep writing both, the text will be harder to read. At some point, we, as a community, should probably consider a gender-neutral version of the word just to simplify these things.
You may point out that this site itself is "Vidar's Gothi". That is a name chosen for its symbolism. It conveys an idea. The Silent One happened to communicate with me on multiple occasions and instructed me to make the web site. Since He is not known to be very talkative, I took Him very seriously. Such direct interaction with a God or Goddess is not necessary to be a Gothi. Again, it is something you do and not an official office.