100% Margin Equity Percentage and Margin Equity Question

I’ve been reading up on Margin Equity Percentage and Margin Equity in my E*Trade account. Despite reading everything I can find, I’m left with one lingering question.

Say I have $1000 as my Net Account Value, $1000 in my Margin Equity, 100% Margin Equity Percentage, and $1000 in Net Cash. Is that MY cash? I can withdraw that $1000 and put it in a savings account or something, correct?

I’m having a hard time clarifying what is MY money, and what is Margin money that would charge me interest if I withdrew it.

Due to my upcoming home purchase, I’m liquidating everything I can.

Thanks!