[Lordzy]

I think you are a newbie in samp scripting.
But search well before you post.
Here's the biz system.
https://sampforum.blast.hk/showthread.php?tid=31653
Here's the house system.
forum.sa-mp.com/showthread.php?t=23051
And for help commands you must create it with fuction sendclientmessage to message player.
To add vehicles you must use function addstaticvehicleex.
Well,if you want to make help command and add vehicle go to the website link below.
wiki.sa-mp.com
To learn basic scripting.
That will help you to create /help command and add vehicles