Hi and welcome to you and your new "little angel"! I'm sorry you lost MIckey, that's such a hard time. I know there are others with more experience than I about their dogs being in season, I've only had one girl go into season so my experience is more limited. But we did do it with our current girl and maybe the experience of someone who was inexperienced will feel more reassuring. I lived to tell about it!
Anyway, our pup didn't have her first season until she was 15 months old and she was spayed at 18 or 19 months of age. We don't live in an area where there are dogs roaming around and certainly neutering dogs, maybe too early, is probably the norm so I wasn't too afraid she'd be found by a male dog and impregnated before I knew what was going on. Maybe if you're around intact males during hunting season you'll have to be more vigilant. Once they go into season, you have to keep them away from intact males for 4 weeks, no less. I had a 6 year old neutered male at the same time, he showed no uncontrollable urges around her during her cycle.
I first noticed a drip of blood on our white kitchen floor and that's what clued me in. People had recommended to start checking for bleeding once they reached the right age, which I took to be about 9 months old. You can check by pressing a white tissue or paper towel against the vulva to see if there's any blood staining. I checked now and then but not especially often. Some people say their dogs seem more clingy or their behavior changes a bit when they're approaching their cycle but I did not notice anything like that in my girl. Maybe if I'd gone through it a few times I'd have noticed a change but I didn't.
While she was in season I had her wear these lovely panties with regular human panty liners or mini-pads inside that I could switch out. They didn't seem to bother her and she didn't try to chew them off. When she was outside in the yard or on walks, no pants. I think some have suggested men's briefs with the tail stuck out through the opening work OK, too. The bleeding subsides before they are truly out of season so even if you don't feel she needs the "appliances" after 3 weeks or whatever, she still needs to be kept away from any potential baby daddies.
I used something like these, although this is just to give you an idea, not what I actually used- there are lots of choices on Amazon and probably elsewhere for them.
https://smile.amazon.com/Pet-Parents...%2C155&sr=8-13
Good luck and please come back and share more with us, such as her name and photos are always a bit hit!