How do credit card companies make money

How much do credit card companies earn from sales

Good day,

I am male, 41 years old and currently live from Hartz4.

Since I am not a person who wants to rest on Harz4, and I have worked for years (head of the electronics store), I would now like to try it out on my own with my own ONLINE SHOP.

My question, what is left to me as (profit) after taxes? and what do I have to earn (sales) in order to be able to live on it?

Breakdown of costs:

Commercial costs,

Purchase of goods, 1000 €

IHK, € 50

Tax advisor, € 200

Shipping costs, 200 €

Web costs and web storage, € 100

Other, 100 €

Total monthly commercial costs, (approximately) 1650 €

Private costs,

Rent, € 800

Electricity, € 100

Tel. And Internet, € 50

Private, € 280

GEZ, € 20

Insurance, € 400

Credit, € 200

Others 150 €

Total monthly private costs, (approx) € 2000

That makes monthly costs totaling (about) 3650 €

Now my question

What is left to me as (profit) after taxes?

What do I have to earn (sales) in order to be able to live on it?

What sales should I have DAILY?

Can someone please tell me what and how much I have to earn, and how much I have to give in taxes, and how much turnover I have to make and at least cover my TOTAL monthly COSTS?

Please please, only serious answers

Many Thanks ;-)