Let's say I have a decently competitive main keyword, not exactly longtail, its 3 words. I want to rank 1-10 eventually for this keyword. Would it be beneficial to my website/blog if I were to also target relevant long tail keywords with less competition through some of my posts also, or just keep plugging away with the main keyword only? For example, lets say my main keyword is: trips to alaska If I also target long tails that are relevant, and make posts about them too (such as "cruises out of alaska", etc), is it gonna hurt my work towards getting number 1 for "trips to alaska"?
Yes it is a good idea to target low competition long tail keywords early on. The search engines will see the relevancy even if your exact main keyword is not used. They will see overlapping words and complementary words. It looks spammy if you use a certain phrase across all pages.