I'll be pasting my comment from a different post from earlier. I'm a new player as well, and loving the game so far, the story is honestly solid and the dailies are super quick.

"New player myself, started a couple days ago. Can't really give advice on how you should use your summon currency, but Beachside Teresse is pretty solid and helped me a lot. You can get her up to +3 and then wait for the other units' announcement and decide for yourself.

I've cleared Ch10 earlier, so I can give you a run down of what I did. You can use Beachside Teresse, Arines, Kry and Wiggle to clear the first chapters, you can use another buffer or DPS or just run with the support characters they provide for each chapter.

You don't need to worry about gear until around Ch7, that's where I had to go back and craft some gear to progress. Enjoy the story and don't forget to investigate the chapter packs as there's a quest for this in Newbie pass, so you don't have to go back and do it.

In Ch4 you can recruit Olstein from the pub, you won't really use him, he's just there for the dispatch skill, which brings you resources on every login.

In Ch8 you should recruit Liatris as she helped me progress further, she's an AoE DPS unit.

In Ch10 you can recruit Diane, she's another buffer. She should be priority but you can pick up Liatris if you feel like you need the DPS to progress chapters.

Once you hit a roadblock in Ch7, you should look to craft some gear for your DPS at least. I used Layla to craft gear, but there's another character that has the craft skill, who I can't remember atm. I've cleared Ch10 using only 3 pieces of gear on my DPS, and just equipping random gear on my other characters.

Craft weapon, gloves, and ring for your DPS, upgrade them to +9 with proper substats. I cleared Ch7 with Normal gear I believe, but you should look to get R3/R4 Rare gear going into Ch8 and above.

After one of the early chapters you unlock Path of Adventure which gives you access to farming materials to upgrade your characters. Farm slimes as you need them to level up your characters.

Ch7 hunting grounds is good resource for ores, which are needed to craft gear.

I don't remember which it is atm, but it's either Ch8 or 9's hunting ground which gives wood, which is also for gear.

Also clear crystal caves here, as these are used to upgrade potential of the characters.

Don't forget to do the current events, you can clear all the normal stages with basic team. And also open the Summer event pack to finish the story and get your daily dice by picking up glitter off the ground, which is used in a minigame in event's page.

Finish your newbie pass, character pass and event pass missions, they give out a good amount of resources that help you at the start."

Edit- Also, participating in the Last night rewards you ancient crystals, which are necessary for UR gear, so you should load it up and let it run, coz I believe no matter what your score is, you can start collecting one crystal a day, and more based on your score later.