Citizenship documents for everyone who might hold ownership, a summary of available funds with their source, any draft ownership structure, and the written business concept. Recent tax filings and evidence of prior business experience help. Do not order valuations, translations or a formal plan yet; those follow the choice of venture, not the other way round.
Label the hypothetical parts as hypothetical
A concept presented as a completed deal wastes the review, because the adviser assesses facts that do not exist. Mark clearly which figures are estimates, which premises are only under discussion and which partners have merely expressed interest. That honesty produces a more useful list of what to secure next.
It also protects the applicant later, when a real submission must describe an actual transaction rather than an early hope. Keep the estimates and the confirmed facts visually separate in whatever is sent to a reviewer, using a marked column or a heading rather than relying on the reader to infer it. Advisers assess what they are given, and a figure that arrives without a qualification tends to be treated as settled.
It is also worth listing the questions the applicant cannot yet answer, since that list is often the most useful part of an early submission: it shows what has to be secured next and, if it is long, it shows that the venture is at an earlier stage than the applicant believed.