What i´m trying is to do it a bit more automatic. By default the sale invoice has a journal named "INV" and i´m creating a custom localization in wich i want to write an XML file that changes the fields i mentioned. Most of the things created by default have an XML ID, but in this case the journals and sequences don´t.

If there is no other way, i´ll have to change it manually

It is customizing. Go to developer mode, and you can change the journals and the sequnce. On thing you will not want to do, is to overwrite the numbering of the journals anywhere. But you can change how the sequence is set up, it is very flexible. And use the standard customization tools in Odoo.

Ok, i´ll do it that way. Thank you very much!

i want to set default account in Journals ? in my own localization ?

How can i set ? Like Customer Invoice Journals

To change default account on journals, you need access as Accounting Advisor.

Then go to Accounting->Setting->Journal and change the journal you want. Default credit and debit.