Raising bonsai from seed is "the slow route", and I do mean years to decades. The "quickest route" to bonsai is to locate a tree or shrub that is 5 to 10 times taller than the desired bonsai, and work to reduce the tree from that point.
Bonsai from seed often must be allowed to grow to 5 to 10 times the size to get the desired trunk caliper. You save a lot of time, starting with a larger, older piece of nursery stock.
Crab apples, apples and pears all make great flowering bonsai, if fruit are too large, you simply remove fruit before it develops. Problem is they take 10 years to 20 years to bloom the first time when grown from seed. Cutting grown apples will bloom in just a couple years.
Apricot & plums will bloom from seed in 5 to 10 years. These culinary stone actually make decent bonsai, but they tend to be a bit coarse in structure. Best for medium to larger size bonsai, maybe 2 to 4 feet tall.
Peaches and nectarines are much more coarse in growth habit, so more difficult to "bonsai". They can bloom in as little as 5 years from seed.
Citrus make excellent bonsai, once they hit about 25 years of age from seed. It takes that long for the ugly green bark to become the nice brown or black bark they eventually get.
Kiwi vines (Actinida chinensis) can be grown from seed. They begin blooming at 8 years or so. You need to let the vines run 20 feet or more fore a few years to develop trunk diameter. Lovely fragrant flowers, old trunks have great bark. The tiny seeds in the kiwi's you buy at the market will germinate, often without stratification.
Tamarind makes interesting tropical bonsai, and is fairly quick from seed, pods available at Latino fruit markets.
i can go on, but point is, starting from seed is slowly route and requires some horticultural skill.
i highly recommend starting with cutting grown crab apples from Evergreen Gardenworks, they will save you years.