advice needed.. what line do i use?

Hi, new to the group and to sea angling...

Need a bit of advice, what line do i use, im confused with all the types and
poundages and what i actually need...
i want to set up 2 reels, i have a multiplyer that i intend o use for boat,
and a fixed spool i wanna use for shore/pier fishing.

Reels are a daiwa sealine 250 multiplyer and a grauvell kronos XL 50 fixed
spool. I would like to use the boat reel for wrecking etc and the fixed
spool obviously for shore fishing which i would do more regularly. For the
fixed spool i intend to use it for a mixture of rock, pier and beachcasting
and fish i intend to catch are everything and anything, basically whatever i
can do and wherever my fishing buds take me since i dont drive and i far
from sea and i aint sitting on a nearby pond allday catching fish i cant
eat!!!

heres what i know already, i need a line, mono or braid, i need a shock
leader, i need seperate snood for making hook lenghts etc. My question is,
what do i need for were and what... i allready have 50lb shock leader spool,
and snood spool of 25lb, i am stuck on choosing a high quality line with
correct poundage for what i need.

cheers