Yes. For RPC-L1 and the GVC to RPC-L1 conversion course, you do not need any logged flight practice before you attend.
The course includes the practical element you need: a minimum of two hours of structured ground and practical flight instruction with a Coptrz Practical Flight Instructor. That instruction and the assessment are flown on Coptrz aircraft under Coptrz insurance, so a spell of bad weather beforehand does not hold you up.
If you do have an aircraft and somewhere lawful to fly, a little practice beforehand can help you feel more confident on the day, but it is not a requirement.
One exception
If you are booked on a GVC course rather than RPC-L1, you must bring your own drone for the flight assessment. In that case getting some recent flying in is worth doing.
After you qualify
To stay current you should maintain at least 2 hours of flight time in every rolling 90-day period, whether or not you are currently operating under an Operational Authorisation.