Priusquam digressus est, Aeneas a rege Heleno quaesivit quae pericula sibi vitanda essent. Ille Aenean ad Phoebi templum manu duxit, deinde dixit: "Nate dea! Pauca tibi dicam, nam cetera fari vetat Iuno....Ubi ventus ad oram Siculam te advexerit, laevam pete! Nam illud fretum duo monstra horrenda tenent. ...Praestat totam Siciliam longo cursu circum ire."
This is passage is part of chapter Andromache et Helenus in Lingva Latina of Pars II Roma Aeterna by Hans H.Orberg. I was only able to translate the first sentence that Aeneas met king Heleno who asked him about what difficulties Aeneas would need to avoid. (correct me if I am wrong). However, I really don't understand the any lines after that. I am just a second year Latin student who randomly got put into a higher class, and my Latin skill is very lacking. I am sorry that I am just asking people for help without giving the necessary context. This is the first time I am using this website, and I just want to get help in Latin. Any help would me much appreciated.
Also, if what is the subject of tenent?