There are two hotels within easy walking distance of the train station, Vagabond Inn and Holiday Inn. Both are located in between the Downtown Plaza mall and Old Sacramento, with restaurants, shopping, etc. within walking distace. You might consider walking to the hotel for the evening, and getting the car rental the next day, especially if the train is running late which is known to happen.

I don't know of any car rental places in the immediate area, but Enterprise will pick you up for your rental. Other car rental companies may do the same.

I just checked on the website, an Avis car rental counter is located in the Holiday Inn lobby.

Not sure if the Avis at the counter is the same as the Avis on 16th St around I, but those guys are great. I rent from them every couple of months. If you don't need the car until Sat am, their rates are generally good and they will pick you up from your hotel. (They close around 6pm on Friday though, so won't work if you need it right away.)

A relatively short walk from the Amtrak station is Old Sacramento. On the water is the Delta King Hotel. This is an old paddle wheeler (who's sister happens to be the Delta Queen that plies the Mississippi River). It has been converted to a wonderful old historic hotel.

Hertz will pick you up at Amtrak too, and they have a direct line connect phone at the Amtrak station, just pick it up and they will come and get you. There are also many hotels near by!

Although there are rental agencies who can pick you up etc at the station, they may be closed when you pull in. We were suppose to get into Sacramento at 4pm on a Monday evening but didnt get in until 10pm, when most things were already closed.

We took a taxi and stayed in Old Sacramento at the Delta King. It was a cheap taxi ride there since it isnt too far. We didnt rent a car during our trip since we were flying out of Sacramento the next day. But Im sure you could get a taxi ride somewhere and be picked up the next morning if need be.

In addition to the other suggestions above, there is a very nice Embassy Suites Hotel on the edge of Old Sacramento - about 3 to 4 blocks from the Amtrak station.