Schengen short-stay (type C) visas are valid only for stays that do not exceed 90 days in any 180-day period. The same limit applies to people whose nationality allows them to enter the Schengen area for short visits without a visa. It is not possible to exceed the limit under a type C visa by getting another type C visa. It is not possible to exceed the limit under a visa-free stay by getting a type C visa. The only way to exceed the 90/180 limit is to get a long-stay (type D) visa or a residence permit.
Type D visas and residence permits are governed by each Schengen country's national law. Most countries require most people to get a type D visa in their place of residence before traveling to the Schengen area. If you want to spend more than 90 days in the Schengen area, the proper course of action is to identify the country where you'll be spending the most time and see whether there is a long-stay visa that applies to your purpose of travel. Some countries, for example, have long-term visas for people who are financially independent and can support themselves without working, but some countries do not have such a visa.