After the base coat is done apply the colour of your choice to the nail

Apply it in similar fashion, first in the centre of the nail and then on the sides. Once all your nails are done, wait for it to dry. If the colour that youve applied is really light, it needs another coat. So apply the second coat and make sure it dries. Find a position of holding the brush that is comfortable for you. Dont stress too much about this, as chances are as you get better youll improve your form.