Help! - My Road So Far

Hello everyone!

Level 21 new player here. All classes unlocked. I am using my gold to purchase only survivors slots.
After stopping at chapter 9 of the story, I have continued to farm resources to focus only on upgrading characters. The only hero I currently own is Daryl at level 9 (I will unlock Abraham tomorrow).
I now have 150 radios and am considering whether to spend them and possibly where. I haven't pulled so far, I've been waiting for the right time to do it but honestly, I wouldn't know who to focus on right now. I skipped the x2 banners from the previous days; now it's Sasha, Hershel and Mercer. Sasha requires relatively few tokens to be unlocked but I don't know how useful her trait will be to me, considering then that I already have Daryl as a ranged shooter.
It would be ideal, though, if I could create a synergistic team of heroes, perhaps thinking of someone who could fit in with Daryl and Abraham. Unfortunately, I couldn't find any specific guidance around and it seems strange to me.
What do you guys recommend I do? Who should I focus on and why?
Thank you!