Welcome aboard to the Community. I can provide some clarifications about the bank balance.
The balance of your accounts will depend on the opening balance and transactions you enter in the system. If the transactions are accurate, but the balance is still incorrect, I suggest checking the opening balance.
It's possible that the amount you've entered during the set up isn't accurate. Here's how to edit:
Click the Gear icon, then select Chart of Accounts.
Locate the account, then go to the Action column and select Account history or View register.
Find the opening balance entry. Tip: If you've got the Date column sorted from newest to oldest, the opening balance entry may be at the end of the list.
Select the opening balance entry.
Edit the amount. Tip: If you're not able to edit the amount directly on this screen, in some cases you can edit by selecting the Edit ✎ icon.