If you're having trouble beating the harder challenges in the other packs, then once you unlock the 'Easy' pack I recommend completing that. All challenges, as noted in the title of the pack, are easy so you shouldn't have any problems with these.
You should unlock the pack very early if you don't already have it unlocked. (I only have 6 stars in Klondike and none in Spider and I completed the Easy Pack).
If someone knows the exact unlock number then could you please put it in the comments so I can edit the solution appropriately?