If you take up bicycle travel very seriously, there is a good chance you eventually will want fenders. Some bikes come with them, some don't. If they don't, you can add them...IF...there are attachment points down by the hubs. Not all bikes have them, especially mountain bikes.

Similarly, not all bikes have the places to which you can attach a rear rack.

You should look for these items. If you get a bike that has them, then you do not have to attach fenders or a rack, but you could if you wanted to later. If the bike does not have those items, then it is much harder to attach fenders and a rack.

My personal viewpoint is that in order to keep my motivation up, I make it a game to see if I can be equipped to ride in all weather conditions. That requires the fenders. I also stop at the grocery store on the way home just because I pass right by it, and that requires the rack. Your personal needs could change as time goes by.

I also have found, at the age of 60, that the bent-over ("aggressive" as they say) riding position is not so comfortable day after day. Personal preference of course, but I would recommend riding one of the "hybrid" or "comfort" bikes to see how you like them.