So it's your first day in Stardew Valley and you are itching to clear up the farm, no surprise there, it looks a mess. But there are a few things to consider before you take your first step.
Some objects require you to upgrade your tools to remove them, so you won't be able to do that until much later in the game. These include these giant felled trees and these huge rock mounds.
Chopping down trees will net you some wood, tree sap and usually a tree seed. The seed varies depending on what type of tree it is.
Smashing up rocks will bag you stone and occasionally geodes, these contain items that may be useful or at least worth some gold.
Cutting out the weeds will give you a chance to get some mixed seeds or fiber, while cutting grass will get you nothing.
Only clear as much as you need depending on if you want materials or plan on planting some crops. This will ensure you have easy access to vital building materials as and when you need them, but also means you won't deplete your stamina too soon, allowing you do do other activities
Once you collect enough wood build a chest, this can be used to store all your goods
Consider building a silo early, as chopped grass will then have a chance of becoming hay stored within the silo itself. This will save you a small fortune if you plan on having live stock on your farm.
Mixed seeds have a chance to grow as a random crop from that season, but that isn't affected by when you collect them. In other words the crop that will grow from the mixed seeds is determined by the season they are planted in, not when they are collected. So mixed seeds collected in spring could be planted in autumn and vice versa.
What do you want to do now?