Treating a new lawn

Don't use weed and feed, imo. The sod needs to be well rooted before applying herbicides.

What kind of grass?

Congrats on the new house. What type of grass?

I’d personally suggest you treat lawn fertilization and lawn weed control as two separate activities and not use combination products like “weed & feed”, which is more of a convenience product, primarily because the best timing of application for fertilizers and weeds don’t always coincide.

Fertilization of the new lawn is not an issue. Timing to be targeted after you’ve cut the grass a couple times this spring, mid-March/early April. How much and frequency of fertilization thereafter depends on your grass type.

The label on most herbicides recommend not applying until the lawn is well established, so you might want to avoid the use of pre-emergent herbicides until this fall and be careful with post-emergent herbicides as well. Read the label. Maybe others will have a different opinion as you lawn was laid in Oct, but even though we’ve had a warm winter, I’m not sure your lawn root system is well established yet.

Cut your grass at recommended height for what ever type of grass you have - that’s important - don’t scalp it. Important for the health of the lawn and weed suppression.

New house/new lawn, might want to obtain lawn soil samples and have LSU AgCenter analyze them for base-line info and recommendations - $10/sample. Lots of soil gets moved around during house construction. Soil sample boxes can be picked up at the independent retail plant stores in BR (Cleggs, LA Nursery, etc) - instructions inside the boxes. You get results that note any nutrient and pH deficiencies in your soil, if there are any, and recommendations on how to correct them, specific for the type of lawn grass you have.

ETA: Centipede. Cut at a height of 1 1/2 to 2 inches. Fertilize no more than 1 pound of nitrogen (N) per 1000 square feet per year. I do 1/2 lb N in early April and a second application of 1/2 lb N around July 1. If by chance the “x” lbs of N per 1000 sq ft is confusing, to determine how much fertilizer to use for 1/2 lb N per1000 sq ft, simply divide the % N on the fertilizer bag into 50. Example, I use a LESCO 15-5-15 (N-P-K) on my Centipede lawn so 50 divided by 15 = 3.3 lbs per 1000 sq ft of lawn per application.