What @Daisuk and @xenosapien said. Also, start easy and take one project at the time. Look around if there are modul/synth building workshops in Thonk or wherever you are. For tuning and calibrating, locate your closest hackerspace or makerspace and ask help from local hackers, they may help you.
No details to kick down ya door … buuuuut… and there is always a but lol my advice would be from the first time I touched a soldering iron. The teacher had us manipulate the iron and play with it.
That’s it for me!
Get a feeling for the way the material moves and aspects regarding life in this area will blossom. Tai chi approach, bro… Tai Chi
watch youtube vids , they helped me a lot.
sodering iron.
lead free solder.
wet sponge thing and a holder.
wire ball thing for cleaning the tip.
turn it off when you arent using it (i forgot that the other day, left it on for hours for no reason)
rubber matt thing with ground wrist plug thing .
solder plunger thing for removing soldered components
copper wire thing for also removing solder , need practice with this but it works well.
and finally , watch more and more youtube vids for different ways to solder components , how to put them in the board , which way they need placing .
start simple , make some audio leads , i built an axo control board , recently a mini atmeggatron , fixed octatrack buttons , modded an fb-01 (with questionable results - if you want to mod something read a variety of pages/forums)
currently , slowly , building an erebus diy
Congrats. You can spend as much or as little as you like and much like modular it’s a rabbit hole of possibilities.
Invest in some prototyping board, desktop power supply (dual output if you can),multi meter and oscilloscope (second hand analog types on ebay go for cheap).
You may not want to invest in this stuff but if your project fails to work you at least have some ways of finding out why.