which are the must have apps for your macbook pro?
It depends on what you will be using it for.
Personally I have always installed the following programs.
Little Snitch - Managing outgoing connections, providing control of which programs are allowed to send data.
1Password - Password manager, there exist quit a few, but I have always preferred this one.
1 Blocker - Adblocker, there are many others, but this one is also able for IOS and can sync rules between devices.
IINA - Video player, personally I like this better then VLC as it looks way better and is more streamlined.
smcFanControl - fan control software
Amphetamine - prevent display from sleeping
CoconutBattery - battery monitor
Alfred 3 - Better spotlight
How should i charge it to make the battery last longer
This article explains battery chemistry well and gives some good advices on how to use the battery the optimal way.
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
The basic idea is that you do not let your Mac deplete its battery below 20% and be carefull about charging it higher than 80%. Personally I use my macbook as I see fit but keep the things mention in the link in mind. So mine is often sitting plugged in while in use staying at 100%. I usually take it off the charger once or twice each month and use it to around 20% and then charge it again. if you can, avoid getting your battery hot as it has a negative effect on its overall durability.