Sorta curious why you need a tank role unless you yourself want to learn it. Unless you are playing blindpick (don't know about coop/ai), you should be able to queue up for bot/sup and get one of those roles all the time (the only time I go to other lanes with bot/sup queue is when asked to swap in champ select). Queuing for jungle might offer different results, but still, normally I haven't been forced to play another roles that I didn't choose unless I agreed to it.
This is just me, but I currently have 3 rune pages and they are very generic.
AD page with Attack Speed Quints, AD Marks, MR Glyphs, and Armor Seals.
AP page with AP Quints, Magic Pen Marks, MR Glyphs, and Armor Seals.
Tank page with Armor Quints, AD Marks, MR Glyphs, and Health/Armor Seals.
None of these pages are highly specific. My AD pages, for example, is not that great on Jhin cause the attack speed does nothing for him. However, it's still possible to play him to a certain degree with this page and it's a good page for most other ADCs and even decent on some top laners. My AP page can be taken as a support or as a midlaner even though it isn't ideal. My Tank page can work support, top, or jungle depending on who I'm playing.
So, with those pages alone, I at least have something for every role. Is it highly specialize to the champs I play? Not really, but it is decent on a wide range of champions. If you plan on playing nothing but MF (or Soraka or Warwick) until you reach Challenger, then make a page specifically that caters to her playstyle. Otherwise, if you plan on varying your champions, a generic page is fine.
Learning to last hit is going to be the hardest thing for playing a tank. As an ADC, normally you start with a dorans blade, but tanks can start with anything from corrupting potion, dorans shield, dorans blade, etc. The biggest thing to learn is how much damage your basic attacks do, but this really applies to any role though. Going into a bot match or a custom and practice CSing will help a lot. One way to get really good at it is to go into a custom and try to CS as Soraka or Karthus. Their projectile is slow, you need to attack a little bit before the minion is at the right health to get the kill. When you go back to any other champion, you'll be able to cs a lot easier.
My top lane tank picks when I'm asked to go top are Nasus and Illaoi. Since I don't know matchups well, Nasus is rewarded for playing passively and getting CS with Q or for being aggressive and pushing the laner out. Most people mindlessly push the wave hoping to get it to tower to negate your Q stacking, but in all honesty if they freeze it near mid and poke when he comes in for cs, they'd do a lot better against him. Illaoi is a pretty safe pick in my mind. Her ult is easily countered by walking out of it or ults that prevent death, but other than that, her tentacles offer sustain and decent wave clear. Both of these champs though are kited quite easily so getting onto a target is their biggest probably. Kayle, for instance, is a great counter to both of them cause she can eat some of the burst to draw you into the fight and then just ult while DPSing you down. Knowing where your character fails is the biggest thing you can learn cause then you can sorta guess matchups even without looking up who generally counters who.