For the potions, (Using strength 3 as an example) Use netherwart, then blaze powder, then redstone. If you want speed substitute blaze powder with sugar. The lower level alchemy you are the smaller chance you have of getting an upgraded potion variant, the higher level you are the higher chance it is. For refined ce you can use books on an enchantment table to get it. You used to be able to get them from villagers however it is removed now