You can go through the below link to start from basics.
https://appium.io/docs/en/about-appium/getting-started/#installation-via-desktop-app-download
You can first start with android as it would be easy to configure and go through some tutorial in youtube.
Once you are comfortable with basics you can refer below description which would help in automating ionic-3 apps.
As ionic-3 apps create webview inside native context.So you won’t be able to test these apps using XCUITest and UIAutomator2 .
You need to use webview context and inspect element using android debugger and safari in android and ios apps respectively.
After converting to webview it would work same as automating in web browser.
You can use below capability .
cap.setcapability(“autoWebview”,true);
Thanks.
