Level 9 Advice to Improve?

I need help on what to go for as my first legendary and what dinosaurs to particularly focus on:
Here are my best dinosaurs:
Level 13 Blue
Level 13 T-Rex
Level 13 Monolophosaurus
Level 12 Gorgosuchus
Level 12 Stegocera
Level 15 Stegosaurus
Level 12 Spinotahraptor
Level 14 Einiasuchus

I am currently working towards Stegodeus, Allosinosaurus, and Indominus Rex. Most likely, when considering what I can get first, it would be Indom, as my velociraptor and t-rex are almost both 15, but allosino’s pretty close as my allo is 13 and my Sino will be 15 by the end of the week. Where should I invest my resources?

Get Stegodeus first. You’d be surprised how this tank will save you in battles against those that does not have it. Probably bump you up until you start battling those that has Stegodeus.