Generally, Breakfast Tea was a good representation of the fomer British Colonies with inclusions from Ceylon, India and Kenya. Ceylon tea brings a light middle flavour, the Assam the deep maltiness and the Kenyan the meaty punch! Today, while Sri Lankan and Indian Assam tea will be in the mix, there are more interesting and better produced teas from Africa, often Rwandan or Malawian included in the blend.
To be frank, the point of a Breakfast Tea is to slap you around the face with a strong, malty brew ...
So, Yorkshire Tea available also as loose leaf (still pretty low-brow) is literally the perfect Breakfast Tea. Flipping that around to a rather highbrow blend that you can make yourself is a simple half and half Assam and Keemun blend. It will be deep, malty, well astringent and slightly smokey. My favourite Assam is Bukhial estate and Keemun Panda No.1 is the Keemun to look out for. Bukhial is quite hard to come by at the moment for some reason.
As an introduction to tea, you could look for someone selling a batch of various teas like a walkaround the world kind of thing ...
There's black, white, green, yellow and Oolong; there's old world, like India, China, Japan, Sri Lanka; New World, Malawi, Rwanda, Vietnam, Laos, even Scotland!; huge producers; tiny processors; esoteric rock teas; the list goes on. Use a seller with a huge variety and follow throught their classifications (black, white, green, India, China, etc) and take a note of the description, whittling down a list of what you fancy.
Since you mention a starting point, I'd say to try out ...
Assam - a really good one SFTGFOP (surely far too good for ordinary people ... https://en.wikipedia.org/wiki/Tea_leaf_grading)
Yunnan Bamboo Temple < South West China, the original Assamica blend that was "stolen" and planted in India
Keemum Panda No.1 < Anhui province smokey tea
Hojicha < Japanese roasted stems ... like Ryvita!
These are tea that I would say I like most if pressed. Curiously, I also like a number of white teas, which on paper are the polar opposite: posh Snow Buds through to plebial autumn sweepings like Shou Mei (Sue Me); light Oolongs, too, especially Milk Oolong. Then really fine rock tea Oolongs, which can cost more than vintage wine.
There are lots of guides that you can google and will explain things much better than me.