You need to specify where the records are coming from (fill a dataSet) and set the LocalPath of the reportViewer:
var dataSet = new DataSet();
using (var connection = new SqlConnection("ConnectionString"))
{
var sqlAdapter = new SqlDataAdapter("SELECT * FROM TABLE1",connection); // Get the records
sqlAdapter.Fill(dataSet, "Table1");
}
ReportViewer1.Reset();
ReportViewer1.LocalReport.Path = "university_project.Report1.rdlc"; // Path to your report file
var dataSource = new ReportDataSource("ReportDataSet_Name", dataSet.Tables[0]); // Specify report's dataset name and the records it use
ReportViewer1.LocalReport.DataSources.Clear(); // Clean the sources so you can use different datasources each time
ReportViewer1.LocalReport.DataSources.Add(datasource);
ReportViewer1.LocalReport.Refresh();