As already stated, if you have the DVDs and they have been "finalized" (such that a standard/set top DVD player can read them), MakeMKV will mux (multiplex) the video and audio together inside an .mkv file as a single transport stream. DVD Video, the actual standard, uses MPEG-2 for video compression, and a properly authored DVD Video "stream" will consist of multiple .VOB files (I think the max size is 1 GB). MakeMKV doesn't compress the video or alter it in any way, it simply multiplexes the selected video and audio into a single transport stream inside the .mkv "container".
If you want some insight into your video/audio after you have used MakeMKV to create a file/stream, I recommend MediaArea's MediaInfo app, free here: https://mediaarea.net/en/MediaInfo
. After you download and install it, launch it and choose the defaults. Then, you can navigate using File Explorer to the file you created with MakeMKV, right click, and open with Media Info. I choose the HTML layout for more info. You can then scroll down through the HTML output and see specifics about your video/audio (e.g., resolution, bitrate, progressive vs. interlaced, if interlaced, if it's top field or bottom field first, etc.).
As far as transcoding, I just finished up a ton of old VHS to DVD conversions using Handbrake. If you want specifics on settings, PM me, and I will be glad to help. But, essentially, I open Hand Brake, choose "File", point it to the .mkv I created after "ripping" the DVD, choose a save destination, use "loose" anamporphic, set the cropping to all 0s to preserve the aspect ratio, mp4 as the container, AVC as the codec, leave the decomb/deinterlace at their defaults, choose CRF (constant rate factor) of 20 to 18 (lower is HIGHER quality), do pass thru on the audio if it's AC3, and nuke any subtitles options, as it's home video and won't apply. I usually do "medium" on the presets/speed, choose "film" on the tune settings, and profile of "high" and "4.0".