Should I say anything having found out (accidentally) problems with my teaching? I started teaching as a part-time hourly paid lecturer in September at quite a prestigious school. I had no classroom experience and had just returned from a long break off career with depression (even did bar work to get back on feet). I am completely over depression and a new person (in early 30s and more confident). 

It was also a return to a subject I had not done properly for 10 years but had conducted research in a different area when working (and in the 9 months preceding teaching). I did desperately want to go back to the subject though having done very well at it when younger. 

The university was short staffed so gave me 8 groups (118 students) to teach and also the chance to lecture in a subject I have never studied before (the lectures being masters level!) I had to design my own lectures - this was all hourly paid.

I taught the first 2 cycles of classes (16 2 hour lessons) without meeting the course leader for any guidance nor even introduction/welcome. I was just emailed handouts with the questions on. 

I was neither issued a contract for the first month (written one) and asked to work without one on grounds I'd be paid later due to admin delay (I was paid!!). Due to this I had no library access, ID card, printing nor login to university facilities. This made it hard to teach.

I was there 2 months and taught 5 cycles of seminars to 8 groups (a lot of teaching). Also delivered lectures in the subject I have never studied (and they didn't give me a textbook for this and I had to borrow one off a friend).In the meanwhile I got a full time job at a less prestigious university (usually lucky given hard job market and timeout).

I felt like my teaching was always very good in the second week (last 4 groups) of the circle, but the first two groups it went badly and I learnt from teaching the first groups and remembered more knowledge as I went on (noticed more what questions needed). Most the students never prepared either which did not help.

When I said I was leaving some groups said 'you cannot, why?' and I received a few thank you emails when I left. 

I logged into my uni email today (not cut off yet and I needed to access it to write a student a reference). I saw an email sent to all students on the courses saying 'all' my lessons would be repeated and taught again by the other two (more experienced staff) apart from one of them with the polite note 'for obvious reasons as discussed with you all in the last lecture'.. This lesson was my strongest for sure.

I've just found out basically my teaching was considered so crap they are teaching everyone again, but worse of all they didn't warn me - if my first lessons were awful, then complaints will have been made earlier.

This didn't happen overnight so I am embarrassed nobody said anything to me so I could try and resolve it or just step in and help me (easier than reteaching everyone). 

Some students really did like my class although it was hard returning after time out.

I am worried about my reputation. Obviously I won't apply for a job there in future and I had no awareness that things had come to this and feel I should have been warned or told. They must have been discussing me (negatively) with a large group of students.
Consider that it may not have been the quality of your teaching that was the issue.

From your description it sounds as if the course was a shambles (probably best not tell us what university this was). Asking an inexperienced teacher to create 32 hours of Masters-level lectures, from scratch, to a large-ish class, without (from your account) any significant discussion of curriculum or assessment?! And hourly paid?  There are circumstances in which each of these would be semi-reasonable, but your account paints a very disappointing picture.

It's quite possible, for example, that the ‘obvious reasons’ are that the course leader/convenor/chair discovered after the fact that you'd omitted to cover a topic that was deemed vital for that course – perhaps the curriculum is constrained by pre-existing assessment or other course dependencies – but which the course leader had never told you about.

The above is of course speculation, but it might be useful for your peace of mind if you can discover if the issue was the quality of your teaching or some other organisational issue. If you are sensitive enough to your teaching, and to its reception, to be able to detect that it improved notably between the first and second cycles, then I would guess that it was at least OK.

Bear in mind, however, that if the real problem was that the course was badly organised, and you badly briefed, then the course leader and their colleagues might be rather sensitive or defensive about it, and you might have to bear that in mind when discussing it.  Also, bear in mind the possibility that – unfortunately and very discreditably – the course administration may have dealt with the problem by blaming the conveniently temporary and now-departed teacher: ‘an inexperienced teacher...; I'm sure I told them what to cover...; anyway, they never asked me....’

If anything like that is true, then it seems unlikely to me that there'd be any longer-term comeback to you. It's even possible that they think of you as someone who was placed in an impossible position but still managed to achieve something.

If you only want to find out details, rather than complain, then an informal setting for a chat might be more informative than a multi-person meeting; and if you know any permanent staff who taught on the course, they might be more usefully indiscreet than the course leader.