EPTryze is one of my favorites in the whole game. when i play him i let the other guy push into my turret for the first few lvls because ryze is weak early game but really strong mid and late. you just have to practice last hitting at your turret (melee creeps take two tower shots and then you autoattack them once and you can kill them, the ranged creeps you auto attack once, let the tower hit them once, and then you autoattack and you get the last hit). dont be afraid to use your abilities to get last hits if necessary.
i think ryze is an excellent pick for mid. i played him from summoner lvl 20-30. you just have to understand what he is capable of (which comes with experience). i dont even try to get aggressive til i am lvl 7-9. you should have boots of speed, and your tear of the goddess, and hopefully a blue buff.
there are some mid champs that have an easier time farming (malzahar comes to mind). but mid and late game ryze dumps on most ap casters just by nature of buiding tanky and damage at the same time.
item wise i start boots + 3 potions, then get tear of the goddess, then build your rod of ages with catalyst first. i dont complete the archangel staff til later in the game usually after 1 or 2 defensive items like frozen heart, abyssal scepter, or (rarely these days) a banshees veil.
i think ryze is a perfectly good choice to learn the game with. he is not difficult to play compared to many other champs and he is extremely powerful. once you get some stacks going on your tear (like i said lvl 7-9) you can start bullying your lane opponent instead of having to play passive.
if you still have questions please ask them or i didnt understand what you were asking please let me know. farming at your turret will not be easy at first. just remember what i said about the melee and ranged creeps and in 10-15 games you will become much better at it. it just takes a bit of practice and you will be able to do it in your sleep.
edit: 'smart casting' makes playing ryze much easier imo. in the 'key bindings' section of the menu that comes up when you hit escape in game, change all your spells to smart cast. smart cast means that when you press 'q' that spell will fire on whatever your cursor is hovering over. you can get your combo out much faster with smart casting, instead of having to hit 'q' and then click on the enemy. this too just takes 10ish games to get used to and then you will never want to go back.
