Union 2 tables

Union 2 tables

Hi Guys! Its me again..  I was trying to use the union all or union instruction but looks like there is an error there.

Basically I have one table:
Table 1:
Document date / document type / customer / product / sales amount / Quantity / Margin / Cost / Brand / Volume

Table 2:  
Document date / Document type / Customer / Debit / Credit / 


And I want to merge a few fields into a new table:
Document Date / Document Type / Customer / Sales amount / Margin / Debit / Credit /


Trying to create a query with union I get an error.

There is any way to create this table even I choose different quantity of fields or the fields doesnt match between tables ?    

Because a the end I need to create a graphic or pivot table with   Sales / Margin and Expenses  to know how is the bussiness and when I will find the breakeven.

thank you guys!