The modern English word "priest" is from the Old English word "preost". That, they borrowed from the Latin "presbyter" which comes from the Greek "presbuteros" which means "elder". In that sense, it is similar to the way the Gothi is typically the elder in an Asatru group.

Back when everybody followed our religion, the eldest member of the group really was the person who had been in the religion for the longest time. These days, the "elder" is often a the person who has been in the group the longest and, therefore, has practiced the religion longest. This is perfectly OK.

However, when most people ask "How to be a Gothi" they are usually looking for something more formal. So, I will write the rest of this as though Gothi is an actual profession that one can study and wear as a title.