-1. The daytime traditional wedding full with elderly people.
This is correct but it needs a verb to make it a proper sentence so you could say
'The daytime traditional wedding was full with elderly people' or 'It was a daytime traditional wedding full with elderly people' This is very good English though!! Very formal and well spoken :D If you wanted to make it sound a bit more casual you could say
'It was a wedding full of old people'. Generally, a wedding is seen as being traditional and during the day so you don't necessarily have to express these but its not wrong if you do! :)
2. - There is the very strict untold rules(or the unspoken rules?) about what guests cant do, especially a dress code.
Not entirely correct but a good attempt!!
'There are very strict unspoken rules about what guests (can or) can't do, especially with regards to the dress code'.
Because 'rules' is plural you use 'are' and not 'is'. I wouldn't say 'a dress code' here since unless it was earlier in the sentence such as
'There's a dress code which guests must adhere too' , 'The unspoken rules are strict and so is the dress code'.
Great job nonetheless!! :D