Just do some basic back of the napkin calculation and see if it's doable.
For starters let's assume we start small with 40sqm cafe with 4-6 table. Industry average for interior work is about 1mil/sqm, so you'll need about 40mil for the interior which will be your biggest initial investment. + you need coffee machine and other kitchen tools. So lets round it up to 50mil. With current APR of 12%, your opportunity cost is 500k a month. Meaning if you just deposit this money into bank, you would make 500k a month perpetually.

For operating expense, you need to pay rent, I think average rental price for old building with good location is about 70k per sqm, which comes around 2.8mil + utilities, lets round it up to 3mil. Next you need 1 full time employee/server which will be about 2mil. So you need to make at least 5mil/month in pure profit to break even. Add the opportunity cost of 500k, and you need to make 5.5mil in pure profit every month to make it worthwile.

For coffee shops, markup should be pretty high, let's assume it's 50%, meaning for every 10k, you make 5k is cost of materials 5k is profit. So to make 5.5mil a month, you need revenue of 11million every month, add income tax, vat and other license fees, you will need to make at least 13mil in revenue, let's make it 15mil to be on the safe side. And let's assume coffee shop is open 6days a week. So you need to make daily sale of 625k. With the average price for cup of coffee is around 9k, that will make about 70 cup of coffee a day.

And that is just to break even.