I can give you the detailed map of everything. However Abruzzo is famous for its majestic mountains, and trains don’t climb well on steep grades, so a combination of train+car or at least train+bus is somewhat necessary to visit a lot of places in the region, otherwise you’ll be stuck down in the valleys.
If you don’t mind renting a car but prefer not to pick up in a big city like Rome or Florence, the town of Avezzano, along the Rome-Pescara rail line has both Hertz and Avis. The main cities of Pescara and L’Aquila, obviously will have more.
The detailed interactive railway map of Italy is below. Click on the region of interest (Abruzzo in your case) on the map displayed. Once the Abeuzzo map comes up, you can zoom in and see the names of the stations which are displayed with yellow dots.
The red lines are main lines, the blue lines are complementary lines. If dotted line, the railway is not electrified and will utilize diesel trains.
Buon Viaggio.
https://www.rfi.it/it/rete/la-rete-oggi/La_rete_oggi_regione_per_regione.html