As long as you go through the entry formalities, you can get the first salary when the company pays wages at a fixed time every month. For how many days to get paid, it depends on the time when everyone joins the company and the time when the company pays wages every month.
Salary is the employee's salary. It is the wages due to employees in fixed labor relations, and it is the labor remuneration paid to employees by legal employers in the form of money according to the provisions of laws or industries or according to the agreement with employees. Therefore, even if you work for less than a month, the company will pay you according to your attendance days.