I want to expand my champion pool across all lanes especially top and I would like to invest my time in learning the ones that are usually safe /good picks in almost every situation examples, orianna, ahri mid etc. All suggestions are appreciated.
Top
if you ban 
JG
if you ban 
top
-Ranged harrass and farm
-Scales well so even if you lose lane he will be a threat late game
-Very useful abilities, thus even if you lose lane you are still useful to team
Jg
-Good at clearing camps
-Very supportive play style thus always useful
-not really countered by anything
Mid 
-great wave clear
-Passive offers saftey
-super useful ult
Adc 
-Super safe lane phase
-E offers safety
-Great mid game, shitty late though
Support 
Malzahar mid is easily the safest pick. A lot safer than Orianna. He counters every assassin except a good Fizz, and can safely farm in any bad match up.
Imho another extremely safe pick is Gragas. Whether he is in the jungle, or top, or mid, or support, or ahead, or behind you know he will still be useful and make a play happen somewhere. He does so many things well and his ult is so useful that you can never go wrong with a Gragas pick.
Ahri/Ori/Malz are great mid for obvious reasons. Always good, always safe. If you get good, Anivia is an amazing pick.
Top lane boasts Gnar (leap/safe farm) Darius (he has counters but typically can hold his own pretty well if he holds his aggression in check), and Poppy because she's so tanky, fast, and can block mobility which helps with ganks.
Jungle has nunu, shaco, and Zac. Very easy to avoid counter jungles and collapses and very effective ganks/disengage if things go wrong.
ADC is easy. Xayah, Tristana, ezreal, Lucian.
Support - Rakan, Janna, Blitz, Thresh. Rakan you have to be good with, Janna is as brain dead as it gets, and no one ever wants to get near a blitz so he's pretty safe. Same for thresh.
your most comfortable
