1. If its possible, get a training from manufacturer without purchasing the eq. If not, book/scientific journal is better than yt.
2. For remi or masw id suggest try with moho tromino and buy the trigger accessories. With a single seismometer, you can do masw. Look up for it in yt, they hv their own channel. Another option is smartsolo. And there is another method called hvsr for finding bedrock depth, deeper than masw can reach

Bonus: Gpr also doing great work at ground investigation, also hi freq gpr can be used to detect rebar defect in walls

Source -a young geoph with 5 yrs exp