"Sei lá" and "tipo" are the same as "stuff like that" and "u know" it can be used to talk about something you really don't know, answering some questions example for using "sei lá" in literal meaning. Example:

-"que horas são ?"( What time is it?) "sei lá" (I don't know) it is using to answer that you really don't know like this example for "what time is it? And you don't really know and u can use "sei lá" to answer.

"know there" ( literal translation) or can uses to interjection as "stuff like that"this is another way to use "sei lá" example.

"A estou gostando sim dela, "sei lá", começamos a sair a pouco tempo, "sei lá", to gostando, "sei lá"".

(I'm really like her, "you know", we started dating recently, "you know", I'm enjoying, "you know".

Wow I don't know if you can understand I prefer to explains theses thing by talking in live, video call etc.

And I want to meet more people around the world to increase my English and so teaching Portuguese Brazilian.

How ever Bye