I have communication issues. Especially in a new team, it takes lot of time to grasp what others are saying. During design discussions and post scrums -
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: