There are 2 main options you can choose from:

- make the chaos set, which will give vh ctr (and dmg) for every weapon type. Having -4 points total for each status, they'll last for 13 seconds, so you don't wana get hit. But that's the point of glasscannon sets like the chaos: having the potential for a LOT of dmg, while being vulnerable yourself. But if you learn how to dodge effectively, it's the 2nd best set out there (after the black kat, but that's harder to get [and not just for beginner players]).

- make a defensive set, like vog, grey owlite, with focus modules, the trinkets. This will require you having trinket slot upgrades, though.

You could try making one of the thirsty six 5* gunner sets, all of them give med gun ctr and med gun asi with either med gun dmg, or vh dmg vs 1 of the 6 monster family types. Keep in mind however, all of the gunner sets have resistance vs one status, and negative res vs another, so they are situational, and would require you having more of them if you want to cover all areas, plus they only give boost to guns, so your blazebrand wouldn't get any extra bonuses.

The seerus mask, from the downloadable content, operation crimson hammer, gives ctr med and asi low for guns, if you have access to it, you should consider using that.

(You didn't mention having bombs, but the volcdemo and mad bomber sets give vh ctr to bombs. The mad bomber is almost the same as the chaos set, though, it has no curse negatives -which rarely matters- and only gives vh ctr + dmg to bombs, so no real point in making it.
The volcdemo is a good save option for bombers on the other hand.

The kat helms also give ctr low to bombs, but making any kat gear other than the black is a waste.)

Keep in mind, that lvl 10 4* weapons do damage more than 5* weapons below lvl 8, so if you won't have enough rads to heat them up, leave your weapons at 4* for the time being. (if, for nothing else, to keep their ctr med from being at lvl 10).