Definitely look into your local library for story time and other activities they host that your baby is old enough for. We also go to indoor playgrounds. You have to pay for it but they have specific areas for different age groups. And our son ends up meeting kids his age and they play together a little bit.
I take my daughter to the park sometimes close to when schools let out because that’s when the families with multiple kids (older and younger) are usually there. That way she gets to interact with the babies/toddlers, but can still get to see how the older kids interact with each other and the other equipment. I’m going to try to sign my daughter up for mommy and me dance classes soon once I talk to dance. She loves dancing so that should be fun. And then when she turns two next year I want to sign her up for soccer for spring and then swimming for both kids in summer.
Second libraries! Maybe seeing if there's a tumble tots or mommy and me type program
Check to see if your local library has storytime. I just started taking my 14 month old son to it twice a week. It's been the best activity for him yet. I am also a SAHM and we get bored these days.