Let me get it (or this) straight. This means that I am going to restate what I just heard from you in order to be sure that I understand you exactly.

It means 'Let me be sure I understand it correctly'

"I need to be sure that I understand what you mean."

Hello. How are you ? I teach English in a college, and you ? I could help you to improve your spoken English. It is free of charge. I just want to meet new friends and know their cultures, such as : interesting places, education, food etc. I am not an online teacher, but I am ready to be your speaking partner. Please add me & talk on Skype directly : aliagil1

"Let me get it straight"= let me say ( something) so it is clear.. Example > Let me get it straight to you guys again : I don't like anyone talking while I am teaching. Let me get it straight with what you said just now . You don't like her at all ?