Proper grid layout is:
container>row>col-*
If you don't use columns don't add "row"

All columns are 100% width on mobile

col-md-3 (25% width on desktop, tablet)
col-md-9 (75% width on desktop, tablet)
col-md-4 (33.33% width on desktop, tablet)
col-md-8 (66.66% width on desktop, tablet)
col-md-5 (41.6% width on desktop, tablet)
col-md-7 (58.3% width on desktop, tablet)
col-md-6 (50% width on desktop, tablet)
col-md-6 (50% width on desktop, tablet)
col-lg-3 (25% width on desktop)
col-lg-9 (75% width on desktop)
col-lg-4 (33.33% width on desktop)
col-lg-8 (66.66% width on desktop)
col-lg-5 (41.66% width on desktop)
col-lg-7 (58.33% width on desktop)
col-lg-6 (50% width on desktop)
col-lg-6 (50% width on desktop)
col-lg-3-6 (25% width on desktop, 50% width on tablet)
col-lg-3-6 (25% width on desktop, 50% width on tablet)
col-lg-3-6 (25% width on desktop, 50% width on tablet)
col-lg-3-6 (25% width on desktop, 50% width on tablet)
col-lg-4-6 (33.33% width on desktop, 50% width on tablet)
col-lg-4-6 (33.33% width on desktop, 50% width on tablet)
col-lg-4-6 (33.33% width on desktop, 50% width on tablet)

Adding "align-items-center" class to the "row" will center cols vertically.

col-lg-4 (33.33% width on desktop)
col-lg-4 (33.33% width on desktop)
col-lg-8 (66.66% width on desktop)

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Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

Heading

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.