u/MannerFine5048

I’m installing a hardwire dash cam and opened up my fuse box cover see this black box. Anyone know what this is?

I’ve got Bermuda grass. Had a lawn guy come for a few weeks and place pre-emergent, fertilizer and was cutting my lawn biweekly but charged $200/month. Thought that was steep so I bought my own mower and want to take control of treating my lawn but needs help. I’ve got these dry spots and weeds are growing. Just came here for some of your expert advice for a newbie to lawn care. Any advice is appreciated.