Tax on original investment amount?

New to trading shares so hopefully someone can answer this question please.

Have tried to find a answer on Goog and HC etc without too much luck.

Hypothetical Scenario:

An individual investor (not "trader") purchases $1,000 of XYZ Ltd shares at $1 each (1000 shares)

XYZ Ltd shares go to $2 each approx 3 months later. Portfolio now worth $2000 on paper in account.

Individual now decides to sell half of shares (500 @ $2 = $1000) to get back original investment amount.

Remainder of shares kept for a longer time frame. (I understand CGT and the 1yr time frame etc)

Is tax payable on receiving this original $1,000 investment amount back?

Have read conflicting info. Surely this is just the return of capital with no profits materially realised at this point so no tax payable?

Thanks for any clarification

Cheers