I am new to Piano and sheet music in general so I downloaded a "simple version" of Fur Elise to play as I already know how the tune goes in my head. Presently, I only play it with my right hand.
A few questions please:
Right in the beginning there is a number "5" on top, then to the right a "2" and then two "1"s in circles. Those numbers seem to be in a few different places, what do they mean? I'm guessing they mean fingerings but why are some in circles and others not?
Theres that big curved line, I think its a slur, right on top from bar 1-4... does that mean I hold the sustain pedal down for that whole bit?
In bar 9 and 10 there is a "1 block" and a "2 block", I googled it and (correct me if I am wrong) but that means when it repeats play the "1" the first time and the "2" the second time, yes?
Lastly, what does "poco moto" on top mean and is it relevant?
the numbers are indeed fingerings. The circle indicates that the hand position is changing.
The long curved lines are not sostenuto pedal markings, they're "legato" markings. Legato means that you play the marked phrase smoothly note into note, without spaces or rests between the notes.
You're correct that the numbered measures near the repeat sign are the first and second ending marks. You play through to the repeat, playing the "1st ending" and go back to the matching (opening) repeat, playing through until you hit the first ending, instead jump to the 2nd ending and play through.
First of all, it should be noted that the edition you have picked is no paragon of typesetting. All of the notes are there, but...
The time signature has been changed from 3/8 to 3/4, with all note values doubled. This is probably to avoid scaring beginners with intimidating-looking notes that look short or fast.
The eighth notes are beamed in pairs, rather than in groups of six or three. Technically, beaming is just a stylistic choice. However, longer beams have the connotation of unity, emphasis, and flow. (More graceful, less plodding. You should only feel one emphasis per measure.)
In the last line of your excerpt, the octave E's are written in the top staff, suggesting that they should be played with the right hand. Nearly all other editions would write part of that sequence on the bottom staff, so that the left hand shares some of the work of the ascent.
Tempo indications, such as Poco moto, are ideally typeset in a bold serif font. ("Poco" means "a little" and "moto" means "motion", so the indication is that you should push it along a bit.)
The fingering markings are usually less prominent. The circled indications appear to be a non-standard way to emphasize the "tricky" fingerings to get right. It's the equivalent of buying a textbook with highlighter scribbles already printed.
There's nothing wrong with learning to play a simplified version of the piece, but if you are curious about the details (good questions, by the way!), it's worth consulting a more authentic edition. Some better examples of scores that I've found: 1234
To answer your other questions...
The big curved lines are indeed slurs. They indicate phrases that should be played legato, and how to shape the notes into musical "words", "clauses", and "sentences".
The original manuscript of Für Elise is lost to history, and the closest thing we have to the original is someone else's chicken scratch. As you can see, the slurs have been added by editors. Your edition's phrasing marks go against the consensus, if you compare against the example scores I've cited.
The slurs do not indicate pedaling. Holding the sustain pedal for E and D♯ would result in a horrible mess. Pedaling would be indicated by either └─────┘ underneath the grand staff or by Ped. (to depress) and * (to release). In the introduction of Für Elise, the pedaling happens to coincide with the arpeggiated chords in the left hand.
Advice: a common beginner mistake is to use the pedal as a crutch to mask crappy technique. You should aim to make the phrasing as good as you possibly can without any pedal, then use a light touch of pedaling to add polish. (You might want to use even less pedaling than what Beethoven originally wrote, since modern pianos are more resonant than pianos in Beethoven's time.)
Your interpretation of what happens after bar 7 is correct. The first time, play the "first ending". Repeat, and the second time, skip to the "second ending".