In my opinion, if you're a low elo/lvl or just have little experience with the game or the dynamics of botlane, it's better to go a non-conventional botlane -cough cough- (
) and someone like
,
,
, etc. All of these champions have fantastic synergy with Mordekaiser/other melee/nontraditional carries. The reasoning behind this is because botlane is probably the most nuanced role in the game, basically meaning that there are a lot of rules/mechanics/playstyles you need to familiarize yourself with to get the maximum effectiveness out of a traditional ranged carry botlane. When you play a nontraditional/melee carry suchs as Morde, a lot of those dynamics/nuances are largely irrelevant due to the fact that you should be able to win most lanes due to brute force (given your opponents are not highly experienced with playing botlane). Also, familiarize yourself with the best spots to use pink wards, the best spots for green wards, sweepers, etc. Never forget to upgrade/swap out your trinkets when necessary (swapping out ward trinket for sweeper when you obtain your Sightstone, upgrading your sweeper later on). Familiarize yourself with the best situational items for your scenario, for example, if the enemy team has a lot of mitigatable CC that can potentially be dangerous for your carry, you would want
, if they have a lot of magic dmg, it would be best to opt for
, etc. etc.
Also one last tip for supporting.
is BUSTED. As long as the enemy team has at least 1 AP threat whatsoever, it's generally a good idea to grab a Locket sometime throughout the game. Don't rush it (unless they have more heavy magic dmg) but definitely try to prioritize it relatively early because the shield it gives and its gold efficiency is just phenomenal and can potentially be a huge fight changer, especially when coupled with
or
.
Good luck.
EDIT: Forgot to mention botlane synergy. Synergy goes an extremely long way in the botlane. Picking the right champions can nearly win you your lane by default (I'm looking at you
and
.