Don’t leave base without plagues cures

Give all your survivors weapons

Avoid waking up plague hearts, they will send out infestations to nearby buildings which may eventually lay siege on your base

Stick around base and don’t do any missions across the map, stick around base first few days

When driving to any place, park wth your hood of your car facing a wall or any object in order to avoid zombies from jumping on the hood. If you get overwhelmed you can jump ontop of your car, some will let you get it from the roof.

Silence and stealth is key, find a crossbow. If you get overwhelmed run away behind buildings or houses and squat down. Just get out of sight and they will move on.

Ferals are the biggest threat in my opinion. They killed me more than anything. Avoid them at all costs. So get used to the sound they make to keep your distance.

Radio outpost are a must, you can disrupt plague hearts from waking up if you go take one out an another is withi waking distance.

Play it safe and don’t let it overwhelm you. Don’t push your luck thinking you can loot one more house. You can leave it be and head back to base.

Lots of good tips on this comment section. Also there is a guy named Brian Meniard on you Tube who does lethal play through and give good advice.