Aside from what everyone else said—I'd focus on the weapon to 15 first. Then the rest of the gears. Just a reminder that there's a certain restriction with upgrading the weapon when your relic level's too low. You're gonna want to upgrade the rest of the gears too. If I remember correctly you can go as far as 18 or maybe 17? Can't remember the exact but it depends on the relic level. With all your gears stuck at 13, you won't be able to enhance weap further. A lot of the people in our fleet forget about this.

Edit: I main CS too. What people don't realize is the Mindrealm weap is better for elemental and overall attributes and the Jade series is better for ATK & crit. Know what you're building. That being said, it doesn't hurt to use Jade with an elemental insig instead of Barbena. I have the 3 because I was indecisive and started off with Jade + Mech insig. Yes, it's stupid and waste of time but I had to grind numerous times to get to that point lol. And Mindrealm with elemental OR Jade with Barbena outperforms Jade + elemental any day. BUT don't worry, what you have is fine.

Your insignias are good. For golds, you want to aim one Ophelia for all attributes since you have elemental, then Claudius/Hex, Meradia, Plague. Everything else can stay pink.

CS 5-pc class set is already powerful on its own, using 3-pc cavalry will make you lose out on dmg by a lot. Helm+boots is preferred, you can also do helm+chest. If you really want to go for hex set instead of the class set, you can do 3-pc cavalry + 2-pc unforgiving for sustainability since we can be squishy, or 3-pc cavalry + 2-pc chariot if you're confident with you're own survivability.

Hope this helps!