Yes! Foundations is designed for any child who is ready to learn to read. The ABCs and their sounds are introduced gradually. Students do not need any prior knowledge before beginning the Foundations curriculum, just the ability to speak English and an interest in learning about letters and reading.
In terms of pacing, the beginning levels of Foundations are geared primarily toward Kindergarten students. Younger students will usually need to progress more slowly through the activities, breaking the lessons into smaller chunks, and we encourage those who choose to start Foundations A in pre-school to take a very relaxed approach, letting the child's level of interest and enjoyment determine the pace. The goal is to use Foundations A to begin exploring some foundational skills in a playful way, rather than to "get through" the lessons at certain pace. You might only want to spend a few minutes at a time if that fits your child'd attention span.
Use the handwriting activities, large-motor only, to introduce the child to how the letters 'feel' and add a kinesthetic element to learning each phonogram, but do not worry about whether the child masters how to write any of the letters at this stage.
If you'd like to start teaching your child about sounds and laying the groundwork for reading but aren't sure you're ready to start a curriculum even informally, you may want to consider Doodling Dragons: An ABC Book of Sounds.