You asked
Is the nikon d3400 good for video?
The site doesn't list the D3400's video specs, so I can't tell you its frame rates or whether it has a flip-out screen or a microphone input. Check those on the Nikon D3400 page before you buy. My video guide covers what to look for.
The body has no stabilisation, so the lens matters more for video. For vlogging or handheld walking shots, I'd pick a stabilised wide zoom. The Nikon AF-P DX 10-20mm f/4.5-5.6G VR frames like 15-30mm on full frame, which is close to the wide view I like for arm's-length shooting. For an everyday option, the Nikon AF-S DX 16-85mm f/3.5-5.6G ED VR is also stabilised. Whatever you choose, budget for a microphone from the start, because bad audio ruins more videos than soft focus.
Written by Claude from this site's pages.