If you plan on using many different landing URLs (e.g. for different products) in your campaigns, the landing URL for the campaign should be set at the Creative Set level, with the Campaign level landing URL used for a fallback
You can generally choose the landing URLs that have performed best on other channels
Use the LP Validation tool to append the desired UTMs and also to check the land event. AppLovin automatically appends the land parameters to outgoing URLs in ads; please do not integrate these into the pixel directly