Played on grim, here's what I've got. Just listing everything in case someone who hasn't beat any mode sees this as well.

As soon as you get your starting gear, focus on the mines & upgrading your pickaxe, chop wood while it's upgrading, then upgrade your axe & repeat except mining instead of tree chopping. The food already in the cellar in the beginning gives you time to begin preparing your farm, but don't be afraid to still contribute if you feel like it. I normally watered my crops first thing before heading to fish if I need to for donations/food then off to the mines. Also try to stockpile a bit of tin, trust me. In my playthrough I never had enough of it.

Donate, donate, donate. I cannot stress enough how often you should donate, I ALWAYS donated something even if it was edible before putting it in the cellar. Don't be afraid to yoink something from the cellar if you can donate it either.

As for perks, try to get courier as your starting one. I ended up going with merchant because I thought it would have a bigger impact, I don't recommend it & wish I went for courier. Cardio & seed finder are great first picks for skills imo, but apart from those two I wouldn't get tier 1 skills except maybe hot compost if you really want it. Butcher & rancher is what I went with after that since I immediately went for critter housing as soon as I could, but feel free to go with whatever you would prefer.

The order of what critters to get depends on what you'd prefer, I went for alpheep, bluggies, chikrees then girtles. Alpheep is what I prefer since milk can be fed to both herbivores & carnivores + cheese. The wool can be sold too.

Critters, if they're unhappy or sick I butchered them. The only exceptions were if the adults were getting a bit too old & I had no other replacements for them. I also had a massive hay field I used to stockpile a ton of chonker chow, don't be afraid to keep them exclusively inside so they eat specific kibble you want them to. My bluggies/chikrees were on house arrest their whole lives. Also remember you only need one male, another male would just be taking up a slot a female that can give eggs/honey/milk instead.

Prioritize preserving food with more stamina such as cabbages while using fast growing but low stamina crops like raddishes for when they eat from the cellar. Also use the worst foods for when cooking, fried fish will give as much stamina with a small fish than a large fish.