How do you level up primary and secondary fast?

Elite sanctuary onslaught.

Go some defence mission that people are doing, like saturn helen. Also if you got relics, pick a defence mission from the menu so you will be doing 2 things at once. Your teammates killing stuff (mostly) also contributes to your weapon progress.

1. If you kill something, then the exp (affinity) is split between your warframe and what you got the kills with.

2. If your allies kill something, then the exp is split between all the gear that you have equipped.

If you are playing solo, you eed to do the work yourself and get kills with the weapon you want to level up to leverage #1. (There are some techniques with like stealth kills that can help here, but they require some finesse and details that might need specific warframes to work efficiently.)

If you are playing with others (even just in public games) a fast way to level up equipment is to leverage #2 by:

• unequip things you don't want to level (e.g. your melee in your case, since you level those up easily), so that it doesn't soak up exp from your allies killing enemies.

• join a mission with lots of enemies, and your allies kill them.

Therefore, some common options are:

• Hydron on Sedna, a Grineer defence mission

• Sanctuary Onslaught with Cephalon Simaris.

• I find The Circuit works decently well too (but you are restricted in what you can choose, so you won't always get what you want to level up, but when they are offered you can pick weapons you want to level up and let them soak up some exp).

• Sometimes a long mission (like defence, survival, inteception etc) can get a fair bit of exp too. Fissures of these sorts are often decent sources of exp (less efficient than other options but you also get to open relics)

Doing those options is decent, because they are fairly common for other players to join too, and so you'll have a team to work with and all mutually help each other get exp. They rely on the common conception that these missions are somewhat worth doing, so that you can semi-regularly form squads randomly with strangers in public games, and hence get the benefits of team-play.

Hydron on Sedna, sanctuary onslaught, elite sanctuary onslaught

If you have Ivara and some silencer mods you can do stealth kills on Sedna Adaro. With affinity bonus active you can max out 2 weapons in one go.

You need to use them more. If all you're doing is killing with your melee, your other weapons won't level.

Unequip every weapon except the one you want to level and head to ESO or SO.

If you have access to Sanctuary Onslaught or Elite, with a affinity booster. Then take Zephyr or Vauban and suck enemies in and fire away at them. Use Zephyr if the weapon you are trying to level is weak.

Helene Saturn or Hydron Sedna are two very popular "bring whatever you want" leveling nodes. Grineer Defense on a very small galleon tileset. People usually just do 10 waves really fast and extract since Noxes start spawning at 10.

While Sanctuary Onslaught [Elite] can be much much faster, you're at the mercy of what random squad you end up with. If someone brought a frame to nuke the whole room, you could max your weapons in 1-2 rounds. If everyone brought unleveled weapons and refuse to nuke since they want the exp for the weapons, it'll be slow and people will probably leave after just 1 round. Although if you're farming that place for Khora or Vandal weapons you can do two birds with one stone. Also Sanctuary Onslaught requires a level 30 frame, so no leveling your frames there.

If you're not even up to Saturn yet, you may want to play in squads more often so that teammate kills give you exp for your weapons.

Use high range Vauban or another frame with a grouping power. Put some punch through on the weapons if needed. Load up ESO. Gather enemies. Fire into the cuddle puddle.