Any techniques on how to end the discussion in post scrum due to time constraint when I am not clear what was discussed?

When there are varying opinions and I still don't understand how to proceed next, what to say?

If you're the decision maker, you should figure out which option you like best and communicate that. If you don't have the information you need, get it by asking questions like, "For each outlined option, what are the primary trade-offs?" If you're new, you can preemptively "shield" that question by saying something like, "Sorry, I'm new so I need more clarity on how this all works." From there, you can ask the question I outlined before and similar ones.

I also recommend this discussion on being more active in meeting

When there is an alignment and I am not confident if I have understand correctly, what to say?

Verify your understanding by asking about it! There is a lot of value in having other folks in the meeting further validate their alignment and general points (you'll be surprised) - I have a very concrete example on how to say that here.

Some phrases I like to use:

1. I try to come into the meeting with a clear idea of what the desired outcome is:
   1. "The purpose of this design review meeting was to get agreement on X. Do we feel we got that?"
   2. "We have a few differing opinions here. Person X is the DRI for this, I'll assign an action item to them to make a decision and document it here by X date"
2. Confirming something:
   1. "Let me try to say that back to you..."
   2. "I'm not sure I understood that, could you say it again?"