Answer: Weed and Feed products are most effective when applied when the grass (and the weeds) are actively growing. For this reason, wait until early spring to apply your weed and feed.
If the seeds you're referring to are grass seeds, plant them in spring, about 4 weeks after you've applied weed and feed to your lawn.
You didn't identify the type of tree you have in the front, so I can't guide you about pruning. If you submit another question to this forum with the name of the tree, I can offer specific pruning suggestions.
Best wishes with your landscape!
Q&A Library Searching Tips