What kind of cream should you use? I've got a little container of fresh table cream. Carbs per 15 ml are 0.6g. and it does have dextrose in it (last ingredient) Is this ok to use?

The best cream is fresh, natural heavy cream. Ideally it should contain nothing but cream but most unfortunately do contain aids to whipping...stabilisers and so on. I would avoid cream with added dextrose.

It would be best if the dextrose wasn't in it, but OTOH, I just checked my cream, it's Grade A Ultra-Pasteurized Heavy Cream. The ingredients are heavy cream, carrageenan, mono- and di-glycerides, cellulose gum, and polysorbate 80. I'd rather mine didn't have all that stuff in it, but it's as basic as I can get in the supermarket for heavy cream. I've used it all the while I've been LCing.
I bet all the extra stuff in my cream are stabilizers and preservatives. Good luck on your LC journey!!!