Make sure that you regularly spend time clearing the land to provide room for your farm. You'll earn crafting materials in the process, such as Stone and Wood, but it takes a lot of energy. Spend roughly half your energy making room for your expansion, especially at first, and make sure that you build a Chest to store it all. Do leave some grass growing, however, as later on you'll need it for Hay.
Community Center Quests
Play for a few days, and you'll witness a cutscene upon entering town. Check the community center, which until that point will have been locked, and you'll discover a golden piece of paper. You can't read it, but that's fine. Go home and catch some sleep, and in the morning you'll find that you now have a message from a wizard. You'll find him in a tower, located to the south of your farm. Make a visit and you'll gain the ability to read scrolls located in the community center building. They outline quests that you can complete for various rewards, including some terrific stuff further down the road.
Farming Means Growth
Upgrades are tempting, but they're costly and don't work as a good starting point. Instead, spend your early days focusing on crops. If you grow a sufficient number of crops in the Spring, around your fishing and foraging activities, you'll reach the Summer season with a lot of resources. Those you can spend on additional seeds on the very first day, and their yield will give you the wealth you need to finally purchase tools and exciting upgrades.
Fishing Fun
Once you reach the second day, you'll receive a letter. You can travel south from Pelican Town after that, and you'll meet up with Willy the Fisherman. He gives you a fishing pole, which allows you to fish and potentially earn income of more than 300 gold per day (plus more besides, if you eat food and replenish your energy so you can keep at it). Early in the game, that extra income will allow you to invest in faster means of earning money.
Foraging Fool
When you reach the end of the day and your chores are completed but you still have time on the clock, make sure that you forage for a bit. Check for plants you can harvest for quick energy, or to serve as something to sell for gold at the market. Particularly early in the game, such activities can go a long way toward get you started along the proper path.
Spawn any item
If you name your character item values surrounded by brackets. EX: [645][499][163] when game references your name, it will spawn items instead. In this example there are three items. You don't always get all three, but sometimes you do. You'll always get the first one. You can also name an animal while buying it for a one time spawn. Then you can rename the animal after. If you don't want to have a weird character name you're stuck with, then this can be pretty nice.
Stardrop Fruit locations
Search the indicated locations to find a Stardrop Fruit. They will increase your maximum energy by 34 points.
Pay 20,000G to Krobus the merchant in the Sewer. Note: To get the key to Sewer, donate 60 artifacts to the museum.
Catch each type of fish to get a fruit from Willy.
Find every book and item to complete the Museum Collection.
Reach the 100th floor in the mines and look inside the treasure chest.
Earn 2,000 Tokens through fishing, mini-games, or a merchant. You can then purchase a fruit from the merchant at the Stardew Valley Fair.
Get married and get your spouse to 13/12 Hearts. Speak with them in your home to get a fruit.
Present your spouse with a gift on their birthday, then speak with them in your home to get a fruit.
Purchase a Rare Seed for 1,000G from a rare merchant on the northeast edge of Wizard Tower. Plant it during the Fall. Get a Sweet Gem Berry from the seed, travel to Secret Woods, and cut the wood using a steel axe. Then, donate the berry to the statue in the Secret Woods to get a fruit.
Strawberry Seeds
Halfway through Spring, you can attend the Egg Festival. Make sure that you've saved up a fair bit of money by that point, and find Pierre at his vending area. He'll sell you Strawberry Seeds, at a rate of 100G apiece, and you should invest whatever you can afford in that lucrative item. Then you should plant the seeds and harvest the berries they produce. Each berry is worth 120G when you sell it, and each plant can produce new berries every two days or so. It won't take long to recoup your investment.
Various Steam Achievements
Complete the indicated task to unlock the achievement.
Achievement
How to unlock
A Big Help
Complete 40 'Help Wanted' requests.
A Complete Collection
Complete the museum collection.
A New Friend
Reach a 5-heart friend level with someone.
Artisan
Craft 30 different items.
Best Friends
Reach a 10-heart friend level with someone.
Cliques
Reach a 5-heart friend level with 4 people.
Cook
Cook 10 different recipes.
Cowpoke
Earn 50,000g
Craft Master
Craft every item.
D.I.Y.
Craft 15 different items.
Fector's Challenge
Beat 'Journey Of The Prairie King' without dying.
Fisherman
Catch 10 different fish.
Full House
Get married and have two kids.
Full Shipment
Ship every item.
Gofer
Complete 10 'Help Wanted' requests.
Gourmet Chef
Cook every recipe.
Greenhorn
Earn 15,000g
Homesteader
Earn 250,000g
Joja Co. Member Of The Year
Become a Joja Co. member and purchase all the community development perks.
Legend
Earn 10,000,000g
Living Large
Upgrade your house to the maximum size.
Local Legend
Restore the Pelican Town Community Center.
Master Angler
Catch every fish.
Master Of The Five Ways
Reach level 10 in every skill.
Millionaire
Earn 1,000,000g
Monoculture
Ship 300 of one crop.
Mother Catch
Catch 100 fish.
Moving Up
Upgrade your house.
Mystery Of The Stardrops
Find every stardrop.
Networking
Reach a 5-heart friend level with 10 people.
Ol' Mariner
Catch 24 different fish.
Polyculture
Ship 15 of each crop.
Popular
Reach a 5-heart friend level with 20 people.
Prairie King
Beat 'Journey Of The Prairie King'.
Protector Of The Valley
Complete all of the Adventure Guild Monster Slayer goals.