Support Vector Machines (SVM) are a class of supervised learning algorithms often used for classification or sometimes regression tasks. Generally, you first need to build an SVM to either classify a set of samples into their respective classes (SVM for classification) or fit a set of data samples to an expected target (SVM for regression). In either of the above case, you need to use part of the entire data to train the built model and used the remaining data to test the trained model. As for the label, in the case of supervised learning (for classification problems), the labels should be decided by an expert.
Kindly see the following article for SVM application: "Adaptive context aware decision computing paradigm for intensive health care delivery in smart cities—A case analysis"
SVM is a supervised machine learning algorithm which can be used for classification or regression problems. It uses a technique called the kernel trick to transform your data and then based on these transformations it finds an optimal boundary between the possible outputs. Simply put, it does some extremely complex data transformations, then figures out how to seperate your data based on the labels or outputs you've defined.
in addition to the comments above, you can also have a look at the ARDUOUS workshop series. They address the labelling of data needed for classification tasks. I think you can find a lot of useful materials there.