In the Lisbon area I have kayaked in:
Lagoa de Albufeira, a sea lake very calm, good for beginners.
Arrábida: beatifull in all accounts, you will be tempted to lay in the beautiful beaches.
Sesimbra: this a kaykaking hot spot (sea kayak) with a very active nautical club where you can rent or join group kayaking . Depending on the route sea can be rough and wind strong. Again beatifull beaches.
My kaykak : a OcenKayak Malibu 2 (I know far from a pro vassel)