1. your sql insert statement is wrong, syntax should be
INSERT INTO table_name (column1,column2,column3,...)
VALUES (value1,value2,value3,...);
2. you need to add SSRegCgehars column as well, since it is not allow null values
INSERT INTO Student (SSId,SSName,SSGender,SSFee,SSTraining,SSDate,SSRegCgehars) VALUES (@SSId,@SSName,@SSGender,@SSFee,@SSTraining,@SSDate,@SSRegCgehars)
3. when you set values of parameters you need to assign it with correct data type. for example if you have datetime column in database, you need to convert string having datetime to a DateTime object and assign that as value.
cmd.Parameters.AddWithValue("@SSId", sid);
cmd.Parameters.AddWithValue("@SSName", textsname.Text);
cmd.Parameters.AddWithValue("@SSGender", Gender);
cmd.Parameters.AddWithValue("@SSFee", fee);
cmd.Parameters.AddWithValue("@SSTraining", Training);
cmd.Parameters.AddWithValue("@SSDate", sdate);
cmd.Parameters.AddWithValue("@SSRegCgehars", textregfee);