Been talking to a lot of founders in the pre-seed through roughly Series B range about how to approach PM hiring. Here's a quick post on what I tell most people, in case it's helpful to you too!

Who to hire:

Don't hire a PM until you have 10+ engineers, designers, and scientists. Until then, you should be the acting PM. Keep the feedback loop between you as the founder and your customers and short/tight as possible! Think of your first PM as someone who'll give you leverage once you're no longer able to support all the product needs of your team.
Someone who'll be with you for 4+ years (don't focus on 6-12mo goals too much, you'll hire the wrong person for the long-term)
Generalist PM who's great at learning any arbitrary thing (so they can adjust along with the company as you grow and figure shit out)
Not afraid to roll up their sleeves (write SQL, make wire frames, do support calls, etc.). As opposed to the typical PM you get at FAANG who's mostly focused on large org alignment and influencing leadership
But also don't load them up too much with tactical execution stuff (aka hire designers, engineers, scientists) so that they can focus on strategy and high-leverage unblocking
Also make sure the designers, engineers, scientists, etc. you hire are empowered to co-own the product with the PM. PMs should never be the only ones to write specs, do user research, write comms, etc.

Where to find them:

People who spent the past couple years at companies that are a couple years ahead of where you are (eg: Series C-D SaaS companies if you're a seed/A SaaS startup)
Scrappy / zero-to-one teams at $1B+ companies (eg: Plaid, Stripe, etc. if you're an early-stage SaaS startup)
Mayyyyybe FAANG but check HEAVILY to make sure they actually do real work :)

How to interview them

Reverse engineer hadardor.com/product-interviewing, but focus on the scrappier / zero-to-one type stuff
If you can, do a work trial for a month or two before extending a full-time offer (hard to pull off unless they suggest it themselves. Maybe just tell them that that's an option but don't force them into it)

How to convince them to join:

Enough equity where a 10x liquidity event from where you're currently valued would pay them better than being an L5 at FAANG+ (aka, $1M over 4 years). And hopefully you'll go 100x ;)
1. L6+ at FAANG+ are getting courted for head of product roles at Series B+ companies. They'd be harder for you to close, but can happen!
Obviously inspire them on mission and all that jazz
Send them reference checks on y'all as founders (people you've worked with before, investors, etc.)