Student Pilots
On initial contact with an ATSU, student pilots, who do not yet hold a licence and are flying solo as part of their training, will prefix the aircraft callsign with “Student”. Once acknowledged it should normally not be necessary for student pilots to use the prefix in subsequent transmissions until making subsequent contact with another ATSU.
Student pilots may also re-iterate “Student” on the RTF if they feel they are being instructed to do something with which they are unfamiliar.
It should be noted that, although this prefix is primarily intended for use by ab initio students, the prefix will also be used in other circumstances where, for example, the holder of a valid licence is returning to flying after a significant absence and is undergoing renewal training.
ATS personnel shall acknowledge the initial call, as in the example above, using the “Student” prefix and should make due allowance for the limited experience and ability of student pilots in determining the pace and complexity of information and/or instructions delivered by RTF.
Taken from the manual of air traffic services, I'm sure your instructor will inform you prior to going solo but you should use the prefix.