To play with scripts and patches you can use BlockLauncher, it is the easiest way to use them.
You can download BlockLauncher either on the official GitHub repository or, if you have newer Android versions and BlockLauncher doesn't work, use a modified version of the program from GameHerobrine, which allows you to run BlockLauncher on newer Android versions.
To add a script, go to BlockLauncher, click on the gray key at the top, click “Manage ModPE Scripts”. To add a script, click the “Import” button, and select the script file. Once added, the script will appear in the list. You can enable and disable scripts by clicking on a script from the list and selecting Enable/Disable.
To add a patch, go to BlockLauncher, click on the gray key at the top, click on “Patch mods in-game”, click on “Manage patches”. To add a patch, click on the “Import” button. Enabling and disabling patches is the same as in scripts.