PandaBear, as Bets said, Barkinpark has been here awhile. But good to know you're looking out for the forum! :)
You can check someone's posting history by clicking on their user name, which links to it. The easiest way to check, though, is to just hover your curser over their use name (on a laptop) or click on it (on a mobile device) and you will see a URL for that particular user. At the end of it is a user number that everyone is assigned when they join. It looks like this: https://community.ricksteves.com/users/30997 (that will lead you to me).
Right now, the user numbers are around 907,000+. The lower the number, the longer they've been here. For example, if you look at Bets, she is user no. 29,473. I am right behind her at 30,997. Barkinpark is at 141,498. A spammer would be in the 907,000's.
Most spammers register, get a number, spam and then leave, so if you're unsure, just check their number. If you're still not sure, you can click on the user name link to see how many posts they have written. If it's below 10, chances are it's spam.