Learn French: Le café est très chaud.

Because le café is a masculine noun. In French, adjectives change to match the gender of the noun they describe. Since café is masculine, we use the base masculine form chaud. If we were describing a feminine noun, like la soupe, we would add an e to make it chaude.

Do I pronounce the d at the end of chaud?

No, the d at the end of the masculine word chaud is silent (it sounds a bit like "show"). You only pronounce the d when you add an e for the feminine form, chaude.

Why does café have an accent mark on the e?

That accent (pointing up and right) tells you to pronounce the e like the "ay" in the English word "day." Without an accent, an e at the end of a French word is usually silent.

Is the s in très silent?

Yes, in this sentence it is silent because the next word (chaud) starts with a consonant. But if the next word started with a vowel, like très amusant (very fun), you would hear the s pronounced as a "z" sound to link the two words.