Don't worry about the disc brake aspect. They require some different tools, but it really isn't that hard. Read up (watch up) on the process for your brake type (different ones have different preferred procedures even though the basics are usually the same) and be patient. And don't forget that if you have DOT fluid, you do not want that getting on anything. It's not instant death
But it will corrode or remove paint. Water or IPA clean well so it isn't that big of a deal. You just have to do it.
If this new frame is 'normal' don't worry about it too much. The principles are usually the same on them all
Press fit parts (headset and sometimes BB) are a new skill set that does require tooling to do safely and well. But there are lots of low-cost but adequate quality tools around. Just don't use a hammer (which can be done but you can screw it up badly). This is in the category where you might just ask a pro to do this part for you if you don't want to buy tools
Di2 does require fitting cables avoided by AXS. But if the bike is designed for it, the routes should be available to you and not a big deal. Get a cheap cable/hose fish tool. Thin wires with magnets make it a breeze. I had to do one recently where it turned out that it was not possible to get the end fitting around the curve from the down tube to the chainstay without removing the BB (it was already installed from a prior build) I recommend running the wires as an early step to avoid these issues.
Get the cable routing tool. Cheap ones are fine. Cutting the fork straight is easier with a guide but you can do it by hand with the right saw. Don't forget how dangerous carbon dust is (wear a respirator and clean up) Again, you can pay a mechanic to do it for you once you've figured out the measurement.
General advice:
- Double check compatibility between parts. If it's all new stuff, it's usually not bad. But as soon as you vary vintages it can get interesting.
- Take your time with a first build. It's not that hard but can sometimes be a puzzle
- Use a torque wrench. Look up all the specs before you start so you're not tempted to cheat. Modern fine components whether metal or plastic (CF) are strong but intolerant of overtorquing. And slipping parts are bad. (make sure you have carbon grip compound)
- At every fitting, use lube, antiseize or loctite as appropriate. Your future self will appreciate it. Look up which is appropriate for each application if you don't know.
- As said before, don't be afraid to go to a pro. If they're any good, they'll appreciate you're trying not laugh at you :-) A few dollars/euro is worth the peace of mind and avoiding damage. (or cheaper than the tool) My first build came with a headset, but I wanted it out to service before the build. I could NOT get it out. Before I damaged something with my own ignorance, I took it in to the shop. When I came back, I asked if I'd done something wrong or if it was damaged. He told me (with a chuckle), that it was REALLY stuck. It took two of them to get it out.
- Have fun doing it. It's a real satisfaction to create your whole bike from parts. Don't worry if you get frustrated occasionally.
