I imported my credit card statement via csv. In transactions, credits are debits and visa versa. How to correct this?

I'm here to help, @Boudream.

Let's ensure that the CSV file is mapped correctly. If you uploaded files with values ​​in one column, you need to move them to 2 columns. This way, your transactions are divided into debits and credits. If you use four columns in the CSV files, make sure the payments are mapped under Credit, and the deposits are under Debit when you import them. Check this link for more details: Format CSV files in Excel to get bank transactions. 

Once done, exclude the incorrect transactions and import the file again. 

You can also create and use rules to quickly categorize recent and past transactions in your QuickBooks Self-Employed account. For the detailed steps, please head to this link: Create rules to speed up reviews in QuickBooks Self-Employed.

Let me know how this goes and feel free to post here again if you need further assistance in importing your transactions in QuickBooks.