This may be a dumb question, but I've never really done much in the way with followers in Skyrim.

So currently, I obviously have Lydia as a follower. She is at my home in Breezehome, and I am currently off solo adventuring in The Reach around Markarth.

Since Lydia was left behind in Breezehome, and I don't currently have access to her without going back to Whiterun, can I still hire another follower?

I'm not sure if the 1 follower at a time means just one follower in your "party" at a time, i.e. 1 active follower at a time, or if you can only just have one follower available period.

Only one follower - if you told Lydia to 'wait here', then you can't have another follower. If you told her that 'its time to part ways', you'll be able to hire another follower.

Yes, I told her "it's time to part ways" - so like, I still have Lydia, but she is not actively following me. She's currently a house ornament in Breezehome - none of her gear is currently equipped, she's in her typical "stand around and wait for me to come back and tell her to 'follow me'" mode.

Okay cool, so I can get another follower. I knew that for sure there could only be one active follower, I just wasn't sure if I could hire a second follower if the 1st follower is "inactive"

When you tell a follower 'it is time to part ways' they'll tend to head back to where you first hired them,.

Yea, I think Lydia is an exception that she goes to Breezehome if you own it.

Thanks for the replies!