In the early episodes, whenever the Voyagers are in time jump, neither their clothes nor number of personnel match when they jumped or land.
No explanation is ever given for how Bogg and Jeffrey are able to understand all the languages and be understood no matter what country they land in or what era, even in English-speaking places - since dialects, colloquialisms, and pronunciations can change significantly over time.
At the beginning of each episode the Voyagers are in their usual clothing even though in the course of most episodes they switch out their clothing to blend in and do not always end the episode in the same place or era where they began.
In most cases, Jeffrey and Bogg seem to have no problem in obtaining clothing from the time periods in which they Omni into. In some cases, they are provided by the people that they meet, but more often than not, they acquire them by means not revealed in the story line.