For CQB, I stick to 1x optics that I can comfortably run with both eyes open - I've used XPS3, EXPS3 and 552 holo replicas all from different brands in totally different price brackets. When outdoors, I started to attach a 3x magnifier but found it pointless in most situations unless spotting at the longest ranges of the site which, at that point, my AEG couldn't even hit. I have a 4x ACOG + RMR on my L85A2 but even then, the 4x is super overkill and the RMR is used 90% of the time.
As you're new to airsoft you'll be surprised (even outdoors) how well your 1x red dot optic works unless you're in a site that offers long sight lines. IMO the only people who end up (really) needing any stronger optics are spotters or snipers.