I think part of it pre-gold ranks is that there is this weird notion that only "the best" play ranked and no one wants to run normal because they can't get any "real practice" in because they'll always be lesser opponents in normals. I find this to be rather silly. People shouldn't be going into a ranked game after just one match on a champ and feeling like they're ready to invest an hour of their time and possibly waste an hour of 4 other people's time.
Go play normals until you know a champ SOLID. KNow the good and bad match ups for it. Then try one or two ranked games. IF you did well, keep going. If you didn't do well personally then step back, tyr to assess why and practice in normals again. I don't understand why so many people think that normals games aren't as intense as ranked. I've had some amazing teams in normals who refused to play ranked because they hated the toxicity.
In your instance, it's managing what you're doing vs your team. Is bot lane feeding? Roam bot when you get a good chance. Is top lane pushing without vision? Get a farsight ward and try to maintain some vision for him. Enemy bot lane just got swept and minions are pushed to tower? Ping for drag and rock out. The single best thing you can do for a bad team is be good and fill in their gaps. Give them vision when you can. Remind them to get wards. Ping REASONABLY, not spamming it. Quick chat input for direction and not flaming anyone. If you're gonna carry their gameplay then you need to carry their attitude too. Be their rock. Be their stability to rely on. It's low rank elo you're in. Most of these guys have no idea what they're doing and those that do will probably go along with the same intelligent call you're making because they know you're going it too so they can commit to the rotation.
You CAN rise, even if you're not in premades. It can work out. I actually was rising better WITHOUT my usual premade simply because I know one or two of them tilt too hard or just aren't a great support/adc. (A 0/8/5 Leona is simply never excusable.) You need to know how to play to the team you get and make the best of it. If bot is pushed back to your t2 but your top is on inhib turret then it might be worth it to hit the top lane, force pressure off your bot turret and see if you can buy bot lane time to farm more. These are decisions you make to try and snowball whatever lead you can get.