Don't know how to play with my friends

Sorry for the semi-rant thread, but I've come to the board once more in search of wisdom. Season 6 is really kicking me in the pants.

Alright, let's see how to get this started. I guess I can start with a little background of myself. I'm Dragonzrkool, a fairly mediocre mid-level player, having played since season 3. I started this game with a small group of friends I have known for ages, even personally in 'real life'. I still play on the NA server, despite having moved to Australia due to this group of friends, and out of partial distaste for the OCE server. I was among the first to hit solo Q ranked, and I ended as Silver, Gold, and Gold. It doesn't mean much, but I consider myself slightly more experienced than the others - most who shy away from ranked or end up low Silver. By no means am I a good player, or a good 'leader' for that matter.

I suppose what I'm trying to say here is that playing with my group is a rather frustrating experience for me. I will start off saying that I rarely openly blame my friends for the loss, and I often am overly critical of myself or some 'cheap mechanic' for losing. We play to win, yet have an extremely high loss rate, and I'd heavily like to blame lack of experience and team communication for it. First off, I don't know what to look for half the time. Tons of information is lost in translation, such as whoever just got level 6, who's missing, what critical spells are on cooldown, possible pathing of an enemy, or overall game plan. Everything seems so spur of the moment, and I often tend to mix my own communications with pinging. I'm told I am not very clear in what information I'm trying to convey at any one time - since I have a higher reliance on pinging as opposed to voice communication from my Solo Q practice. Often things I might say are just completely ignored altogether, or so it feels like, often leaving me not bothering to communicate at all. I question if I am really that difficult to communicate with, which is entirely possible, or if I just lack the means to do it.

Second, I guess comes experience. We have players who started just this season, and others who have been only playing here and there - leaving them rusty. Some don't do some roles entirely, and plenty of them have no idea what to build at any one time. I have a basic idea of individual roles of characters, and how skirmishes and teamfights should go. I can particularly name how any support should work at any one time, but when it comes to the mages and non-ranged carries/bruisers others play I don't know what to tell them. How to build, how to play, and what one should be doing at any one time. I unfortunately expect too much of them, such as utilizing a CC ability to keep a fed person off a carry, rather than going for an enemy carry - and then being disappointed when that doesn't happen, but I don't feel like my advice is followed or I'm giving the 'right' advice.

TL;DR: I don't know how to effectively communicate with my friends, and with the new season - I'm having a really hard time adjusting. I don't know how anything works anymore, and it just feels like the game is a massive snowball fest that I can never get the upper hand on. I'm looking for some friendly advice of how to be not only a better player, but a better friend and mentor as well for this game. I really don't want to keep being frustrated - I want to enjoy this game with them.