There's lots of good points put forward here. However, most of it is from a more experienced player's perspective and might not suit you if you're just starting out.
It's all about meeting expectations. If the host/game calls for something specific...you (the player) are bound to satisfy it. Adequate food/water/clothing for the weather and some other stuff are givens. Quality eye protection and good footwear are mandatory.
When it comes to Hicaps...it comes down to the type of game and the guidelines put out there for that game.
If it's a easygoing/shoot 'em up/newbie type thing...I'm 99% sure it'd be fine (and if in doubt, ask the host). Most of those games are really adhoc and really suit the guys who are starting out, have little kit, etc...
But for the games that are limited load outs, real cap mags, milsims, etc...hicaps have no place (IMO). For some guns (WW2 to note and many SAWs/LMGs) there's no option but a highcap....and so hosts will put cautions on taking pauses to simulate and reload, remove mag/insert/rewind, etc....
As much as having "come on guys, let's not-be-so-serious" fun playing a cleaner form of paintball is the focus for some...injecting as much realism into things is a focus for others. Part of that realism is ammo/resource management, emergency/tac reloads, running dry, etc..
So...again, back to expectations. If uber-milsim guy goes to fun-day newbie skirmish he'd probably poo-poo all the guys in jeans, hoodie and highcaps (he shouldn't...but he probably would). If high-cap guy showed up at a milsim with a bandolier full of highcaps he'd probably get the stink eye...and rightfully so.