It says my monthly limit to buy linden is 30$ , how do i raise my limit?

[SAULGOODiE]

As a new resident, you will have to wait for your limit to be raised. Please read this page for a breakdown of Billing and Trading limits for Residents. 

[SAULGOODiE]

As a new resident, you will have to wait for your limit to be raised. Please read this page for a breakdown of Billing and Trading limits for Residents. 

[KarenMichelle Lane]

Saul's answer is correct. Just start the clock for your automatic limit raise my making that first Linden Purchase below the $30 USD limit. 28 days later you'll be up to the default max.