Evidence-based answer · Last updated · How it’s made
There's no special "start differently for Latin American Spanish" method backed by these sources — the core mechanics of learning Spanish (sound system, grammar, vocabulary) are the same regardless of target dialect. What the sources do support is: build a foundation with formal/classroom-style instruction (which helps with grammar and the sounds English speakers struggle with), and deliberately add exposure to Latin American features — like "vos" and regional pronunciation — since standard classroom materials tend to default to Spain's Spanish and learners typically only pick up other varieties with more proficiency and exposure.
Answered for language learning in general. No specific language was set for this question, so the findings are drawn from general second-language research rather than one language’s literature.
Research on American university Spanish students found that learners, especially at lower levels, were most aware of Peninsular (Spain) Spanish pronunciation features rather than Latin American ones. Only as students advanced in proficiency did they build knowledge of pronunciation differences across the wider Spanish-speaking world.2
Many Spanish courses leave out 'voseo' — the use of the pronoun 'vos' and its matching verb forms, used in countries like Argentina and several Central American nations — even though this is a real, frequently-encountered feature in Latin American speech. One source argues it should be deliberately introduced at the intermediate level so learners can recognize and respond to it appropriately in conversation.1
In plain terms
Explicit, classroom-based instruction in Spanish phonetics (teaching learners the mechanics of how sounds are produced, not just having them listen and repeat) gave English-speaking Spanish students an edge in perceiving and, to some extent, producing target Spanish sounds — sounds like certain consonants (stop consonants, approximant sounds, and rolled/tapped r's) that are known trouble spots for English speakers.5
In plain terms
Students who studied Spanish through a semester abroad (in Spain) gained more in speaking fluency, conversational skill, and storytelling ability than students studying only at home. However, their grammar accuracy sometimes got worse compared to at-home students, and their pronunciation wasn't more accurate either — the areas where formal classroom instruction focuses tended to be where the classroom-only students did better.3
Example
The exact regional accent of English a learner speaks — not just 'English' in general — shapes which Spanish sounds transfer easily (helpfully) and which cause interference. A study of Welsh English speakers learning Spanish found both positive transfers (sounds that map over correctly) and negative transfers (habits that cause mistakes) that were specific to their particular English accent.4
In plain terms
Example
In a study of beginning university Spanish classes, students whose classroom deliberately allowed some structured use of English (rather than banning it entirely) improved significantly more in both speaking and writing proficiency over a semester than students taught in a Spanish-only classroom.6
Now pick something to do it with
Each of these opens an overview of the apps, courses and immersion material worth a look for that — filtered to exactly what the advice above points you at: