Advance payment

You don't HAVE TO do advance payments, it's optional. Read the article in the learning center about advance payments. It's quite a bit of text to read, but then you'll acknowledge.

Surplus, advance payments are not on previous year's taxes, for which you will submit your tax return this year.

Advance payments are for this year's taxes; you are paying an advance on those taxes. But you will not file that tax return until next year.

Indeed, as mentioned above. You should not make any advance payments, and you should read the article about advance payments. Perhaps even the course, which is quite good reading material.

Crash course in the learning center. It's quite a lot to read, but afterwards I think you'll have a good grasp of the theory behind bookkeeping. It's explained in a very straightforward way.