Ahahaha my child! I am here for you!
Nox or Sigma twin machine guns work for your current skill level. Id say get a light element since its a universal type of element, most enemies are affected by light. But unless your a techter or a force, light is your thing (unless you wanna build differently). Get your weapons to level 30 forget 35 unless you really think youll use those that long.
Your next choice of gun will be H1 Missouri's or whatever theyre called. They should be located in the shopping plaza , theyre the only 13* Twin machine guns you can buy at the moment from the plaza. Use the rising weapon badges for them. Rising weapon badge 1 that is. Get those to level 35, there are guides on how to do that efficiently. Those will carry you for quite some time.
Best twin machine guns right now are debatable but in my opinion, Nemesis Bullet is best. Its awakened potential allows for you to tank damage sometimes, like a shield, very useful for us when were using showtime and something slaps us extra hard. But its again up to you.
- You should snag the luxe armor set, minimum, if you have that already you ahould be shooting for the brissa set which you can buy from the shopping plaza, idk which shop sells it by heart sorry. The best armor for us in my opinion is the saiki set. Farm it from SHAQ's. Get the whole set or buy the whole set from players, up to you. Luckily its cheaper now.
- Least to best souls would be Fang Soul, Leopod soul, Soigr soul. You want anything that gives decent RNG power in general. I set my armor and weapons to have modulator (gives every stat a boost), Siogr soul, Noble precision, and Precision 3. (For now) Theres a guide on youtube for affixes. Use it trust me.
At around level 50+ you should be doing Advanced quests, any of them, find groups, dont run through thinking you do alot, you dont. Do them till you unlock super hard, aka, SHAQ's. Grind that until you hit level 75 on both your main and sub. I recommend getting every class to lvl 75 though like I did. I run Gunner/Fighter since its the best set up for high dps, but Gunner/Hunter works well if you die alot, etc, lots of builds.
pm if you need more guidance.