This is a great time of year to begin thinking / planning about how to improve your lawn!  The first thing I suggest is to do a soil test on your yard (something you can do now).  You need to learn what your soil tells you before doing any next steps. Knowing the type and fertility of your soil is the starting point to establishing & maintaining a strong turf that can resist diseases, weeds, moss and insects/grubs and look great without wasting material or $. More info here:Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer
Grub control....  Read the following articles regarding grubs and their control.  FIRST check to see if you really have sufficient #s of grubs to cause lawn damage (by early April).  If you find #s of grubs above the treatment threshold you must decide whether to perform the curative (spring) treatment or wait until mid-summer to do the (more effective) preventive treatment.
How to Choose & Apply Grub Control Products-MSU - info on checking for grubs, curative and preventive treatments and insecticides to use
Managing White Grubs in Turfgrass-Purdue
Take Control of Lawn Grubs w-o chemicals-PSU  - biological grub control info
Your photo shows mycelia which are an indication of a fungal turf disease, but there's not enough information to determine which one.  It could be Pythium Blight - a summer disease or Pink Patch - a spring/fall disease. Here are links to turf disease websites for your review.  I can't be more specific with the information given.
MSU Turf disease ID
Purdue turf disease ID
Turfgrass Disease Chart-OSU
I'm also adding 2 more links to multiple articles on lawn care:
Home Lawns | MSU Extension - lots of good lawn info....
Smart Lawns Tip Sheets-MSU - more helpful info