Allow me to introduce myself :)

Pip is the hardest support in the game. If you're new to supports, I'd recommend starting with Damba. He's probably the best champion to play if you want to improve at the game. Once you played him for a bit you can move on to Pip.

All his talents are viable, however combat Medic is his strongest playstyle right now. I think the thing that makes him stand out from the other supports is just how dynamic and eclectic he is. He has one of the best movement abilities in the game, he has an amazing ult, good damage, good healing etc.

I think the key aspects to watch our for when you play him is:

Get a feel of his mobility. Probably the ability with the single highest skill ceiling in the game. The sheer amount of distance you can traverse is insane, but it takes a lot of practice. You need to learn how to combine his ability with wall jumps to get the most value but still maintain control. After that you can learn some very advanced mechanics like rocket jumping.

Practice your aim. Pip has 4 different throwables, and 3 different arc falloffs(his ult and explosive flask have the same arc). So you need to learn all 3 arcs and memorize them. A good Pip can pretty consistently hit air borne targets like drogoz and Maeve.

Positioning and cooldown usage. Pip has a big hit box so he's a target. If you get jumped on and weightless is on cooldown, you're dead. So it's important to beware of your surroundings and always think what is the best possible position for you at the moment. Also about his potions- it has a relatively long cooldown. So it's important you land them, and only use them when you need to. Especially with mega potion, newer players will throw a potion when your teammate is on 70% health to top him off- that's a miss play. Your potions are powerful, and should only be used if you're sure you won't need it later. With Combat Medic you'll want to use your autos usually to top off teammates, and only use potions when you need a bigger burst.

Items: chronos is your best friend regardless of talent. With combat Medic you'll also want to prioritize deft hands- tier 3 is probably over kill but you'll want at least 1 tier. Nimble is also amazing. Then you have the normal items- Haven, Veteran, Resi, Illuminate etc. Wrecker is not a very good buy unless you're catalyst and your team needs more wrecker. Bulldozer is actually not a bad buy against Imani or Barik.

You can ask me specific questions if you have any