Currently i am hooked into It's Not Easy to Be a Man After Traveling to the Future its my first novel reading about mech and its interesting, i feel like im reading gundam or code geass. and if you also know about a novel that similar to this i would appreciate it "Woman pretended to be man"
Heavy Object - watch the anime first then read the novel Legend of the Galactic Heroes - space opera, watch the new version anime, then the old version which is the OVA, then buy the novel
KNights and Magic https://www.novelupdates.com/series/knights-magic/ About controlling and fighting magical mecha suits~
if there was an translation beside the first chapter I would suggest the fan fic unlimited maschine war Spoiler Wolrds which are included Macross, Gundam(0079, seed, 00...), Valvrave the Liberator, Super Robot War (OG, V) Muv Luv but else I could only suggest knight & Magic, if you want giant Robots in human and non-human form
Skyfire Avenue has mech too, although not to the extent of Knights and Magic 86 Tempest of the Stellar War Magic Robot Aluminare these three are more exoskeleton, mini mobile armor type Saijaku Muhai no Bahamut Hybrid x Heart Magias Academy Ataraxia Hundred i've had Magic, Mechanics, Shuraba in my reading list, but never started reading it. not too sure how it goes
You could also try Forty Millenniums of Cultivation. Though it takes awhile before the MC can actually start refining his own suit. Still, it's one of his main passions.
The Mech Touch, original novel in qidian...the MC has mech system...minimal faceslaping...humble MC...i give it 4.5 star
You can try one side novel https://www.novelupdates.com/series/muvluv-alternative-schwarzesmarken/ The main series' not on Novel Updates but MuvLuv Alternative is guaranteed mecha fighting~