idir wrote: Why don't the forum make a organized course for the new ones like me!
I've learned the cases,but it is not comfortable, for example:every day there is a lesson online after that there are some exercises,
You should start here: D'Ooge's Latin for Beginners
It is a textbook set up the way you would like -- lessons followed by exercises. The answers to the exercises are here: Key to Latin for Beginners
Read the lessons, do the exercises, check your answers and then bring any and all questions you have here to the forum. That book has been very popular in the past, and so there are also a lot of posts already about some of the exercises here in the forum that you could read through, too.