I'm the account owner and can't see all my data Many of our reports and transaction lists are filtered by a certain date range (often last 30 days or the current month) by default. If you are looking for data beyond this range, try filtering by a different date range to view more, or even "All Dates" to view everything.
I'm an invited member and can't see all my data If you log in and do not see all the data that you would expect to see, including not being able to access parts of the site, it's possible you are an invited member who was not given full access.
Please have the account owner (likely the one who invited you) go to Settings > Members under their owner account and mark you as a Trusted Member. Trusted Members have much of the same access to accounts as owners do, including the ability to create and edit transactions and invoices, view reports, and more. Untrusted Members have limited access to these.