Any tips to rank up?

The best way to rank up quickly is to understand how the emblem system works and what you need to do to do well in it.

The Lightbringer emblem is for completing objectives. You need 270 points for Iridescent Lightbringer. Each percentage of progress made on generators is 1 point, though bear in mind that when doing cooperative repairs, your contribution will only be half of the total, meaning that a fully repaired generator with one other survivor will give you only 50 points. So try to repair generators solo if you can. Dull totems are worth 20 points, and hex totems are worth 50. All survivors are also granted 15 bonus points when the gates are opened. So to do well in Lightbringer, I would recommend trying to complete two generators solo, and cleansing 4 dull totems. Or you can complete two and a bit more generators, and cleanse only 1-3 totems, to achieve the same effect.

The Unbroken emblem is simply for surviving. In order to get Iridescent Unbroken, you need to escape the trial without being downed. Escaping, but having been downed at least once, will grant you a Gold Unbroken emblem.

The Benevolent Emblem is for helping other survivors, and is the easiest one to do well in. You need 80 points for Iridescent Benevolent. You start with 35 points. Each safe hook rescue is worth 20 points, and each full heal of another survivor is worth 10. So all you need to do is safely unhook two survivors, and heal one of them, for Iridescent Benevolent. Just make sure that no one dies on hook, since you will lose points if that happens.

The Evader emblem is for evading the killer. This is the hardest to do well in, and also the most complicated to quantify or keep track of your progress in. Basically, you get points for being close to or being chased by the killer, and for stunning them with pallets. It's one of those things that you can't really track reliably or try to farm, you just do well in it if you happen to be in the situations it calls for a lot throughout the match. Most of the time, you will get at least Bronze Evader if you do well during the match, and maybe Silver if you did decently in chases.

Each Iridescent emblem is worth 4 points, each Gold 3, each Silver 2 and each Bronze 1. You need 12 points to pip at purple ranks, which means three Iridescent, or two Iridescent and two Silver, or the equivalent thereof. If you aim to get Iridescent Lightbringer and Benevolent, you will probably pip most games, since it's not difficult to get a Silver in the other two categories, or a Gold in Unbroken and Bronze in Evader. Once you reach red ranks, you will need 13 points to pip instead, so you'll need to do slightly better, but not by much.

As for builds, I would simply advise you to play to your strengths. Use perks that help you do what you enjoy and are good at. Personally, I enjoy a mix of stealthy and altruistic play, so my typical build is Adrenaline, Borrowed Time, Unbreakable and Iron Will or Spine Chill. If you're good at boldness and chases, you can substitute more aggressive perks that will help you in those circumstances, like Decisive Strike and Dead Hard. We'll Make It is also useful for doing well in Benevolent. I'm personally a fan of Prove Thyself, but it only works during coop repairs, which as I mentioned are bad for trying to rank up, so I would advise against it for that reason.