Hey there

[Maximvs]

Hi Lilly and welcome

To answer your question, when you arrive at Cuba, behind the Shipwrite and the swamp is the entrance to see Tia. There are two - and though both will take you to her - one entrance takes you right to her swamp location, the other you have to enter and then run through her swamp to get to her.

In the game many locations you will have to run through cave / tree entrances to go to other locations once you reach an island. Tia is good practice for that

At Level One though, I'd hang out a bit longer in Port Royal in the Graveyard, kill a few easy undead, then kill a few soliders at the fort entrance / the Mansion before taking off too fast