Translation:I saw my doctor yesterday.
Yeah, but please note that if you ran across the doctor in the street then “meet” would be translated as 遇见 (yù jiàn) or 遇到 (yù dào).
There is nothing to report in this case because the sentence was to de assamble with what was there
Yesterday is capitalized suggesting that you start the sentence there. I met my doctor Yesterday isn't proper grammar
1) Is 了 optional for past tense when you use words like "昨天“? Sometimes I see 了 used and sometimes I don't ... so if I said "我昨天见我的医生" would this be ok?
2) If I were to say "I saw my doctor" without a specific time can I say "我见了我的医生."?
Re (1), it can be OK. But the use of 了 can imply the meeting was completed one, like a completed consultation.
Re (2), you can. It will be understood as you said.
Why is le used here? Shouldn't zuotian alone be sufficient enough to imply pay tense?
"le" isn't supposed to be used as a past tense marker. It's used to indicate the completion of a verb, or if used after an adjective and also sometimes after a verb, a change in state.
you literally saw your doctor in the translation, you could also visit your doctor?