As per https://flow.microsoft.com/en-us/pricing/, there is limit to run the flows per month.
If I run the flow from the powerApp, will there be any limits?
The amount limits to run a flow from an app is based on the license your PowerApps belongs to.
The PowerApps Plan 2 license and Dynamics 365 license would include the Flow Plan 2 license, the PowerApps Plan 1 license would include Flow Plan 1 license, the PowerApps for Office 365 license would include the Flow for Office 365 license.
Please check the following article for more details:
So if your PowerApps has Dynamics 365 license or PowerApps Plan 2 license, you could run a flow from an app for 15000 times. If your PowerApps has PowerApps Plan 1 license, you could run a flow from an app for 4500 times. If your PowerApps has PowerApps for Office 365 license, you could run a flow from an app for 2000 times.