Brave Frontier

I started playing 2 days ago. Is there any chance for me to beat the 6 heroes dungeons (Selena in specific) before they go away without cashing out on gems?

I have Phoenix 3*, Selena 3*, Dean 4*, Signas 4*, Il & Mina 4*, Darvan 4*, Faris 4*, and 500k gold
When the evolution fodder vortex opens I'll should be able to evolve a few of them.

Any suggestions/tips for a beginner? I'm lv 27 and at St. Lamia/Cordelica in the story.

Those dungeons are end-game content, basically. The timers only signify when the next of the dungeons will be released (I think Magress is next?), the dungeons themselves are permanent. It can even be a grind with the right units.

Hmm. Keep questing, make good use of Metal Parade (like when you have 30 energy and 2k experience left to level, go into Metal Parade to maximize the runs), and log in daily. Not great with the beginner advice, so maybe some other people have more thoughts.

Oh! And you might as well add everyone on Southperry. The IDs are all scattered over this thread, though it might be a better idea to just post your own ID, since a lot of us probably have full Friends Lists.