Hi
Please don't overload the cage with furniture and mostly ignored pet shop toys. Ideally you have one more hut with two exits or a log tunnel instead than you have piggies - ideally the same. Two exits are important since part of group establishing dominance in any new territory is chucking the under-piggy out of any property that a higher ranked piggy desires. The extra hut or tunnel means that there is always something for the underpiggy, especially when the huts are spaced well apart or the tunnels are lined up like backyard garages in the middle of the cage - the leader cannot physically control them all.
For the same reason, two water bottles at different ends of a cage and hay access that cannot be blocked by one piggy. Ideally you have an area for soft meadow hay to burrow and sleep in and a different area if you want to feed harder, spikier timothy hay which comes with a greater risk of injuries, so it is not ideal for romping. Romping hay is one of the most important enrichments.
However, the best toys and interactive activities are not expensive at all and will give you lots of shared fun. Pet shop toys are all too often ignored and a waste of money. Try the cheap stuff first once your piggies have got their bearings. Enrichment is also a lot more than just providing toys and can happen on lots of different levels. It is a great way for you to enter the fascinating world of guinea pigs rather than reducing your piggies to petting pets.
It is always better to just start with the basics and then build up to what works with your piggies than discovering that you have spent a lot of money on stuff that is not used by your piggies.
You may find these links here very helpful:
Getting Guinea Pigs? Items You'll Need To Buy?
Enrichment Ideas for Guinea Pigs
New Guinea Pigs: How to Best Manage Arrival and Settling In
Our very practical and helpful information collections (which you may want to bookmark) - the links above are part of it:
Are Guinea Pigs For Me? - Wannabe Owners' Helpful Information
Getting Started - Essential Information for New Owners