Here is some general advice about practicing sight reading for bass...
Consistent, Steady Reading Practice
The biggest key to learning to read is to do it every day. It’s all about memory. The more repetition you do, the better. I always feel frequency of practice matters more than quantity of practice. Just running through it a little each day will do wonders. A few minutes several times a day is even better. You will have a hard time if you only practice reading one day a week.
Trial Runs Are OK
When you are beginning to learn to read music, it’s okay to play through the notes slowly a few times without worrying about the rhythm. Try to not do this for too long. Rhythm is obviously a key ingredient to reading music. Playing with a metronome will help you learn to think on your feet more. You will start to look ahead as you read. Without a consistent pulse you will slow down on notes you are less comfortable with and speed up on the ones you know well. You want to know each note on the bass clef and the fretboard equally well.
Pace Yourself When You Read
Practice slowly. Your first goal is to play the music correctly, not fast. Use a metronome to pace yourself. You may start at 50 or 60 BPM and slowly increase your speed. As you gain confidence with your reading skills, challenge yourself. Increase the tempo to 80, then 100, and higher and higher. There’s no shame in practicing slowly.
Mind Your Fingering
Be very consistent with your fingering. Don’t shift your hand around needlessly as you read. You are trying to develop consistent reactions to what you see in the sheet music. If you keep changing your hand position you will delay your progress. As you learn more about the fretboard and gain confidence in your reading abilities, you will know when to shift.
A consistent hand position will enable you to look more at the music instead of your hand. This helps a lot. It's not that you can't look at your hand, but it sure helps when you don't.
Position Yourself and the Music Well
Use a music stand. You should be in a comfortable position when reading. A good music stand helps a lot.
Point the neck of your bass at the music. Keep your fretting hand and sheet music in the same line of sight. If you do need to look at your hand, you only need to shift your focus. Otherwise it’s like watching a tennis match.
Say It Out Loud
Don’t be shy to count rhythms out loud. Don’t just count to yourself in your head. That’s not as effective. You will stop or lose your place. Count out loud. You won’t have to do this forever. In the beginning it really helps. Counting out loud has a physical aspect to it much like tapping your foot on the beat.
It also helps to say note names out loud as you practice them. Try it.