Nice one, what a good start @alexandravart. I see you got some liquin, its good stuff, makes your work dry faster. If you feel your colours are dull, it might be because your brushes contain thinner. Try to use only pure paint with a little liquin, only use the thinner to clean the brushes. Then wipe them thoroughly. Too much titanium white also makes the colours chalky sometimes. For the palette I suggest neutral colour gray, mixing on the white palette, can trick your eyes too :) I hope you had good ventilation, and enjoyed oil painting :)