Yes, the 'd' is pronounced. For native English speakers, there is a very clear difference between saying "I like it" and "I'd like it". Non-natives - especially Chinese speakers - struggle to hear the difference, unfortunately. This is because they expect the 'd' to sound the same as it would at the end of a word or phrase, and they don't realise that it sounds different when it occurs before another consonant. Here's an explanation: The sounds 't' and 'd' are alveolar stops, which means that the tongue touches the roof of the mouth just behind the teeth and stops the airflow for a moment. If this occurs before a pause, the airflow is released, and you hear a clear 't' or 'd'. However, if the 't' or 'd' occurs immediately before another consonant - in this case the 'l' of 'like' - the two consonants merge together. The tongue moves from the roof of the mouth and then glides immediately down and back to articulate the 'l', creating a blended 'dl' sound. Non-natives don't hear the 'd' being released, so they presume that it has been dropped. This inability to perceive and produce sequences of consonants is a particular problem for Chinese learners of English. You need to listen to lots of examples of native-speaker articulation to train your ear to the differences between single consonants and consonant clusters.

Yes, you DO pronounce the /d/. You don't have to pronounce the sound as strongly as "I" though.

First things first. 'I'd like' is not a sentence. It's simply two words. Second, you do pronounce the 'd.'