Yes, amalgam fillings can be replaced with composite restorations. (white fillings)
However, composite restorations are not always suitable- from a strength of material point of view- or if indeed the cavity is too deep. The performing dentist will usually take this into account, and you may need to consider having porcelain crowns instead.
Composite restorations are matched in colour to your existing tooth structure, so it would make sense to whiten your teeth first, so that the composite material can then be matched to your lightened teeth.
I would suggest that discuss this with the dentist first.
For the incisal edge chipped tooth, composite again can be used to build up the chipped area- matching the shade of enamel carefully. Soetimes, however it is not uncommon for these incisal edge composites to chip off again, so it may be worth considering a veneer- for the most long term option. This all depends on the size of the chip. I would advise a dental consultation to discuss the options further.