how to do regression and classification in a same time? I was thinking of doing a job including regression firstly, then doing the classification. I read lots of sources that are saying it is Semi-Supervised learning while I think it is not.
Imagine after doing regression we will reach to the graph below:

we know that there are 2 classes and now the goal is for prediction of the possibility of locating in class 1 or 2. It means that, for the next data that we have, we need to make a classification.
I believe you are just describing standard classification.
Take the image below, the model of the classification is the decision boundary found between the two classes. After we have found this model, using a classification algorithm (clustering or otherwise), for new data we can use it to predict which class the new data belongs to.