Robert - if you are launching anywhere in the Dockyard Port of Portsmouth which is basically anywhere in the Eastern Solent (including Portsmouth Harbour all the way upto Fareham and Portchester I would offer the following recommendations:
1. Do a RYA Level 2 Course before venturing off on your own - it can be very confusing out there and it will teach you all you need to know to begin with.
2. Have a VHF set (and of course a license) tuned to Channel 11 to hear what's going on.
3. Read and understand (and remember) all the local rules - can be found on my website www.qhmportsmouth.com.
4. Sign upto receive Local Notice to Mariners electronically and thus stay upto date - I issue about 60 a year so there is always something to find out about before you set off. For example this week we have issued new LNTM for small vessels like yours entering and leaving the harbour.
Good luck and have fun and get in touch if you have any questions.
All the best
Queens Harbour Master Portsmouth