Favouritse desserts

I have a lot of favouritse desserts.

For example, I like the ice cream very much, but I also I love the fruits,: mango, pineapple, orange, peach, lychee, and so on.

I put a colon in because you list a bunch everything listed after it is a type of fruit. If the colon seems too formal for you, you can also say:
"... but I also love fruits, such as mango, ..." (slightly less formal)
"... but I also love fruits, like mango, ..." (least formal)

"La Crema Catalana"," which is delicious, is similar to a crème brûlée.

You have two sentence predicates where you should only have one. Some other options:
"La Crema Catalana" is delicious and similar to a crème brûlée.
"La Crema Catalana" is delicious, and it is similar to a crème brûlée.

In the summer I prefer a "Macedonia de Frutas"," which is similar to a Ffruit salad, is very good of and taste ands refreshing.

But if I haved to choose one, it will be thould be lychee, thatwhich comes from China,. It is a small fruit with a solid hull, t. The inside fruit is white in color with aand taste as alike pineapple with, and there is a big bonepit in the centre.

This was another run-on sentence, which could be split into multiple sentences in many different ways.
You can say "The inside fruit is white in color with a taste like pineapple," but it is less awkward to say it tastes like pineapple.
Also, you do not need to include "in color." Simply saying "the inside fruit is white" can only mean one thing, so the additional words are not necessary.