Some tips that i find useful: most code can convert nearly 1:1, but don't get so caught up in exactly replicating what you did in dbp that you neglect to take advantage of the improvements agk provides.
Types can include arrays! (Arrays in general are improved.)
https://www.appgamekit.com/documentation/guides/12_array_changes.htm
You can pass by reference to functions!
Things that were only available through plugins are now core language such as sparky's raycasting and ezrotate local/object space rotations, take a good look at the help docs to see what is available
https://www.appgamekit.com/documentation/commands.html
Some things are missing like wrapvalue
but people have posted a number of snippets that give equivalent functionality.
http://games.joshkirklin.com/sulium
A single player RPG featuring a branching, player driven storyline of meaningful choices and multiple endings alongside challenging active combat and intelligent AI.