Furniture:
Getting different color furniture may be a nightmare. It seems the colors Nook sells are the color you're locked to. You have a chance of finding a different color in a balloon or tree, which will unlock it in the catalog, but AFAIK, Nook's Cranny will stay locked to a single color.
Foreign Fruit
Getting foreign fruit is tricky, but not impossible. Everyone has a sister foreign fruit they can get on NMT islands. You just have to visit them often and you'll find them. I don't visit those Islands very much, and I've found at least 3 so far. You can also receive fruit from your mom. In past games, you could get foreign fruit offline by sending fruit to your villagers via mail. It may still be possible in this game.
Dreamies.
if you have dreamies you want, you'll be at the mercy of RNG, unless you obtain amiibos for them.
Last, there are turnips and the stalk market.
The turnip game isn't too bad solo. There will be days you lose some money, but when you get into the rhythm, on average, you'll always be making more than you invest. I recommend
https://stalks.io . It's extremely accurate at predicting your prices and pattern. Because of this, it can guide you to the best time to sell your turnips, incase the next follow price changes are all going further down hill, or if they will get higher than they currently are.
Also check here to make decisions on what to invest:
https://gdoc.pub/doc/e/2PACX-1vRHLC...u4XxYHgfAgS3dx2AnB_vD9vjyVL7f1W9p1kGFwQ0AZZzH
If you're likely to have a random or decreasing pattern for the week, it may be wise to make smaller investments for the week.