The total number of new emojis in 2018 is 157 when Emoji 11.0 is released as part of Unicode 11.0. The version number skipped 6 through 10 (the last emoji release was named Emoji 5.0) to instead use the same number as the Unicode release.
New emojis added in Emoji 11.0 include a skateboard, dna, kangaroo, partying face, parrot, lobster, and more. Finally red heads also get their own emojis, along with bald and curly emojis.
When the emojis will be available to the user depends on the platform. Emoji updates for smart phones are tied to major OS updates while internet platforms like Facebook and Twitter can update their emoji sets at any time.
As with all emoji sets, designs vary by vendor. Here is the sample images Emojipedia created in an Apple-like style to show how they think the new emojis might look like.