Embryology is fascinating and remains important clinically later on, so it’s best to have a sound foundation. However, it can seem quite complicated. I recommend reading a short and simple book first, such as “the “illustrated colour text”, which I really liked and still used in 2nd year (the latest edition is from 2009, so quite old, the latest “at a glance” series is from 2016 – still not quite brand new either). For essays etc., you can use a larger textbook, such as Larson’s Embryology. I used it to look up particular details, and the animations provided with the Student Consult access online really helped understanding.
In terms of 1st year exams at Cambridge at the time, I found it quite sufficient to just learn which embryological structure develops into which structure in the adult. This is what I’ve summarised in the document below.
https://www.slideshare.net/slideshow/embryologycriedingerpdf/9325785