Newby - How to convert DVD ".VOB' files to MP4 H.264?

I have 2 videos (abt 17.75min -1Gb & **15min - 0.9Gb) on hard drive. I can load and can watch in Shotcut. I tried a ‘default’ convert to mp4 but those cannot be read / presented with std Windows Viewer. 2nd attempt started creating an enormous file multi Gb.

I had previously converted a DVD VOB file (0.2Gb) using default settings and got a mp4 (0.17Gb).

What am I doing wrong?