The Little White Train is famous around France. It's a good way to learn the history of Toulon and see the city.
You can spend a few hours and rent paddle boards, catamarans, kayaks, etc.
Take the cable car to the top of the mountain. It has the best view! Theres also a restaurant and some trails up there.
Check out the largest market in Toulon. Open everyday until 12:30pm
There are a ton of vineyards around! The town one train stop over - Bandol - is also widely known for their wine!
Grab a towel + some goggle and head down to Mourillon beach.
Head down to the city center and shop around!