I suck at SF4 2012 but I think Fei long, Sagat and Ken are quite easy to pick up and play with no combo knowledge. People saying Balrog and Guile but I think charging moves effectively is a skill in itself, maybe it just me I never got on with charge characters even on the older SF’s.
Definitely Balrog and Bison, especially Balrog. Easy AAs, difficult jump to AA, easy combos, great normals.
I’d pick ryu
I’m in the same boat as a beginner player.
First character I tried was Gouken, but he has so many different alternatives in his moveset (3 different attacks in his divekick, 3 different counters, 3 different fireballs) that it’s a bit confusing for your first character, so I decided to pick someone with a more basic skillset.
Then I tried Ryu because I think shoryukens are overpowered in low-tier games lol seems like it has priority over any other move. He was fun to play with, but then I realized Ultras are even more powerful in low-tier games doing half your health and no one ever blocks it lol, so I wanted someone I can easily ultra into (ryu’s srk FADC ultra is a bit tricky)
I’m currently trying out Rose, she’s much easier to handle, her ultras are easy to execute (U1 antiair, U2 anytime), although Senku through fireballs was my favorite move of all time lol so I’ll be going back to Gouken after I master the basics with Rose
top 3 easiest
Seth (not the EASIEST, but if you considering difficulty based on winning, then seth is the easiest)
Zangief (once again in ease of winning, he gets harder as you get better though)
Bison
Fei (Footsies and Counters)
Cammy if you want to learn on a rush down character
Ryu/Ken if you want to learn on a shoto
Balrog/Bison if you want to learn on a charge
I wouldn’t recommend grapple characters or anyone else regardless of their “type” because the characters here can teach you a lot of the basic aspects of the game which you tend to lose with the more “complicated” or “situational” ones
Roundhouse and four fingers with which to hit Roundhouse. We in there.
> Easy Chars
o_O
… And where is Fei a rushdown char?
You left out makoto, dudley and Hakan for difficult characters to learn.
Well I may messed that up a little, Fei isn’t t technically rushdown as he is all counters and footsies, but he is still good for beginners. Cammy is good too albeit a little harder due to links. At least you will learn how to properly link using her 
No one mentioning Honda 
At low-mid level play you can do keep doing special moves because people don’t know how to punish them. He has god like hitboxes on his jump-ins and you dont need to be able to do jab hands to steal wins.
Why do you think hes mike ross’s favorite character? No work to win with him.
i’d say easiest out of the characters you like… 1. ibuki incredibly easy to hit confirm from the lk, mk target combo and the lp, mp, fp as well. she also has easy links that you will pick up on the way too; 'til you are getting 1 frame links from the spin kicks. easy mixups you can just cycle through one out of 3 options every knockdown and you’ll hit people. 2. cody pretty much explained in above posts. 3 guile
however in your 2nd post you said how you wanted to play cody, guile, and ibuki in that order… I would recommend that you play them in that order since cody is a really strong character in ae 2012 and will show you plenty of different offensive set ups and also the big damage out put helps. and guile will show you a more defensive play style.
Ryu and Guile are difficult to win with at higher levels. Top 3 easiest are Dictator, Boxer, and Honda. For Dictator there is nothing hard to learn, the only thing that could possibly be said is that his BnB has a few 2 frame links (Whoopie). Nothing hard about learning Boxer. The only thing that can be said about Honda is learning how to properly execute hands.
Top 3 hardest to learn are C. Viper, Gen, and El Fuerte. Viper because of the execution requirement (even Latif and Wolfkrone mess up her instant burn kicks and fients). Gen because of his stances along with hands technique. Fuerte because of run stop fierce and spacing.
OP asked for hardest to use though. That would be Hakan, Dan, and prolly Oni. Learning them may or may not be easy, but they still have to work for their wins. Learning these characters are great and all but at the end of the day they still suck.
I picked up Gen for the hell of it and realized he’s much easier to use than anyone would think. Just start off by using one stance away from opponents (Crane) and the other one up close (Mantis). After awhile you will begin to learn how to use both of them up close.
For the most part you wont be using Mantis at full screen.
I’d also add Juri, though using her Ultra 1 properly or dash escape, requires some skill
Ibuki is easy to learn but hard to master. Her Ultras have frame delays and when the opponent crouches and is defensive things are difficult. Against beginners it is may be easy but against better players it requires high execution. Against Zangief you have no advantage at in frame traps. Not as difficult as Guy though. I made my biggest victories with her but if the opponent learns your game you have to be more inventive. One mistake and there is no chance of escaping. In SFIV she’s much better than in Third Strike