For your Interface I would recommend using Weakauras and Bigwigs.
Weakauras will give you the opportunity to import a lot of helpful visuals/alerts/timers 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.
Meeres Beast Mastery Hunter UI
Here are some useful Hunter macros everyone should have:
Aspect of the Turtle Cancel Macro
You're unable to cast spells while being in Aspect of the Turtle so it might be useful to cancel it sometimes.
/cancelaura Aspect of the Turtle
Misdirection Mouseover/Focus Macro
Spell & Pet Attack Macro
IT'S IMPORTANT FOR BM HUNTERS TO USE THIS MACRO FOR EVERY OFFENSIVE SPELL.
The auto-cast system from blizzard 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. It is recommended to macro these into every important ability while using a pet.
/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 weakauras fitting your own interface preferences and play style.
Wago.io has a huge collection for Hunter: 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.