react-native-elementをインストールする

yarn add react-native-vector-icons
yarn add react-native-elements

react-native-vector-iconsが必ず必要

import { FormLabel, FormInput } from 'react-native-elements'

<FormInput
   onChangeText={(text) => changeInputText(text) }
 />

入力フォームはこんな感じで使う