When to get pre approved?

[David Rabinowitz]

Hello everyone. For the last two years I've been reading books, listening to podcasts, paying down debt (all DONE), and saving money for a down payment for my first investment property. I've decided my first property will be an STR and I'm currently enrolled in the BP STR bootcamp! I'm hoping to start putting offers in late March early April.

Question is, how far in advance should I reach out to lenders for a pre approval.  I've read that I should shop multiple lender for rates, terms etc. and there is a certain window in which it will not hurt my credit.

Thank you all for any input.