Are these lights okay for veg? flower?

[tevfik]

Get a six plugs extension

This supposed to be one unit only. Not six separate.
Anyway, what you have now okay for veg and flower.

I was thinking if I put the extension plugs over that then It would be easier for me to adjust the height as I go... unless someone has a better idea (because that's all I got)

That is not safe and setting your light fixture is another subject, but not confusing. Since you have all you need you can start getting on your feet from now on.
Good luck.