For your Interface I would recommend using Weakauras and Bigwigs.
Weakauras will give you the opportunity to import a lot of helpful resources to keep track of your cooldowns, buffs and debuffs.
BigWigs for having a boss mod helping you to plan your cooldowns ahead of time and be prepared for certain abilities that are about to happen.
Below are some useful Hunter macros everyone should have:
Aspect of the Turtle Cancel Macro
You’re unable to cast spells while using Aspect of the turtle so it might be useful to cancel it sometimes.
/cancelaura Aspect of the Turtle
Misdirection Mouseover/Focus Macro
Hunter Pet Attack Macro
The auto-cast system is super slow on pets and you might miss out so make sure to use this macro.
Another important topic is the pet attacks. You should macro them into all of your abilities when you’re using a pet to guarantee the pet will use them on cooldown and not miss out on damage.
Here is one example for Barbed Shot which can be replicated for other abilities:
/use Barbed Shot
/use Smack(Basic Attack)
/use Bite(Basic Attack)
/use Claw(Basic Attack)
Having good Weakauras can really help you out a lot with keeping track of all the important stuff.
The best is just to find the best Weakauras fitting your own interface and playstyle.
Wago has a huge collection for Hunters: https://wago.io/weakauras/classes/hunter
If any questions come up the Trueshot Lodge is your place. The discord server is by far the biggest hunter community and there are a ton of friendly people helping you out with your questions if you ask nicely.