I use a variety of manufactuers' paints - Tamiya and Mr Colour Aqueous are my 'go to' paints but I have other brands too (all acrylics). On a personal level I just cannot get on with Vallejo Model Air at all and don't use them: they just didn't work for me any which way or how.
An airbrush would be an excellent addition at some point in the future, but you may need to save hard for a decent brand of airbrush and compressor, which is vital. Don't rely on the compressed air cans.
As to actual colour, I think we can get too much into 'accuracy' - but what is 'accurate'? Personally speaking I don't think we should beat ourselves up too much about not having the proper FS or 'official' colour since in real life paint weathers, it fades, it looks different in different light, each batch is bound to vary bit by bit. So far as my modelling goes, I will select a shade which, in my eyes, is close as I can get it. I know that can be heresy to some, but really, if it's a lemon yellow where there's a lemon yellow, where there's a dark grey there's a dark grey, for a sky colour there's a sky colour, for my own modelling, it suits me.