For automatic drafts, the contestants will not be distributed until everyone joins the league.
For manual drafts, the draft clock does not begin to run until all league members have joined the league. Likewise, the commissioner will not be able to activate the draft manually until the league is full.
For commissioner drafts, the offline draft can take place anytime, anywhere, and in any manner your league chooses. However, the draft results cannot be entered on the site until every league member has joined the league.