Note: Never look at the sun without proper eye protection. If you're using unprotected binoculars or telescopes you will experience INSTANT permanent eye damage.
Another warning: "back in the day", they used to have "solar filters" that you would screw in to the base of an eyepiece. Don't use these. Especially with larger apertures, the scope would focus all that solar energy (heat) onto the filter. It would heat up (predictably), and potentially crack (unpredictably). Even an instant of concentrated sunlight could permanently damage your eyesight.
Today, we most often put solar filters (approved mylar, film or other material) at the front of the telescope, filtering the energy before it gets into the scope.
Always look for a certification of safety/compliance when buying solar filters - or buy from a reputable astronomy company. I normally recommend buying from a telescope company, but amazon works if you're in a hurry.
In Southern California we can get quick delivery from our locals:
The key to all the solutions is the filter on the substrate (mylar, film, glass). Solar sunglasses are inexpensive because they may only need a couple of square inches of filter. Filters for an 8" scope, for example, will require 30 times mor filter material. "Cells" to hold the filter material in place are often expensive - there are DIY options for mounting the film.
Solar Sunglasses
These are inexpensive and perfectly good solutions for eclipse viewing. You really don't need magnification to enjoy watching the progression of chunks being eaten out of the sun. They can be purchased for a couple of dollars each when bought in bulk.
Eclipse Binoculars & Eclipse Telescopes
I don't recommend these. I do recommend buying good binoculars or any decent "celestial" (night) telescope. You can buy filters with custom housings ("cells") or DIY housings to place on your equipment. Exception: H-alpha solar telescopes.
Custom Solar Filters for your Telescope (or Binoculars)
These are produced by a handful of manufacturers and sold by a variety of resellers. Google will get you to them. They have reliable non-slip housing for the filter material. The housings generally add $40 or more to the cost of the filter (depending on size), but they tend to be much more reliable than DIY housing-mounted filters.
Film/Mylar for DIY (telescopes or binoculars)
Solar Film https://www.seymoursolar.com/#/ - this produces a warm yellow/orange tint to the sun.
Mylar - produces a white solar image. https://astrozap.com/collections/baader-solar-material-to-build-your-own-filters Astrozap's website has a lot of information and products. Baader Planetarium solar mylar is sold from a variety of resellers as well.
DIY: Building the Filter Housing/Cell
If you're handy, the thrifty option is to build your own housing/cell to hold some solar film/mylar you buy cheap by the sheet. Cardboard and duct tape can save you some money. Also buying a sheet of filter material lets you cover your scope and the leftover can be used to filter your binoculars and create eclipse sunglasses.
How to build an inexpensive filter cell
DIY Solar Eclipse Viewing/Photography Filter (video)