There shouldn't be a problem with acidity, unless you live in an area where this is generally a problem. However Its easily remedied by applications of lime. You can use sand and it can be left when its time for seeding, however before seeding- it should be raked or shoveled into the top layer of soil - so as to not have a soil layering problem later. If the sand layer is too thick, the new seedlings will root into the sand , and not go any deeper. Same with mulch, it must be mixed into the soil.

Thank you! Our yard is a bit acidic from pine trees surrounding it. Are there certain types of sand or mulch that I should be looking for? I would plan to use the bare minimum and then rake it into the soil before seeding, as you suggest.

Mulch that is designed to amend the soil. Many such products at your garden center. Washed -'all purpose sand' - is usually mid sized aggregate and good for your situation.

I have "play sand" in a sandbox; sand bags purchased from Home Depot. Do you know if that would fit the bill? Could I also add some of this sand to my garden area? We have clay-like soil.

Hay or straw purchased at a farm co op. We use this when camping. Straw is cheaper than hay. It will rot and help your seeds. We always use straw when available.

Play sand is ok. Sand bags are sometimes filled with low grade “dirty sand” which turns into a brick over time

Just an FYI, but pine trees do not make a soil acidic - no plants do. That is a very persistent garden myth. Soil is acidic because the underlying mineral content is acidic. And the amount of rainfall has an impact as well - areas with heavy rainfall tend towards an acidic pH; arid areas tend to be more alkaline. Mulches of any kind have minimal impact on soil pH unless they are incorporated into the soil and even then only certain kinds will have any measurable effect.

btw, most plants, including turf grasses, prefer slightly to moderately acidic soil conditions. That provides the greatest access to necessary soil nutrients.

I'm going to be completely, 100%, anti sand. You might need way more sand than a light dusting to keep the water down. If you get enough sand you will reshape the drainage in the yard. The very last thing you want is to redirect rainfall into your house or even just flowing toward the house. Sand is a permanent game changer.

I would use mulch. Mulch can be piled high and wide without making any permanent change to the drainage. Why? Because mulch is organic and will decompose over the next year or so until it is gone. You might be able to get mulch in multi-yard quantities for free from a local tree trimmer.

Of course mud is caused by water. Can't you just not water the muddy spots until after the party?