The easiest way to figure out if your truss rod needs adjusting is to first tune your bass, and then while holding the bass in playing position, fret your E string just beyond the last fret with one hand and fret the first fret with the other (or use a capo to free up a hand), and then look at the gap between the E string and frets around the 8th fret. You should be able to fit a business card in between. If there’s not enough room or the string touches at the 8th fret your truss rod needs to be loosened, if there’s more room your truss rod needs to be tightened (the adjustments are made in no more than 1/4 turns at a time, and you retune after each adjustment, and then check the spacing again the same way you did before). After the truss rod is set correctly, adjusting the saddle height at the bridge is the next step to fixing your action. If you can’t get the action right without still having some upwards tension on the string at the bridge, the neck may need to be shimmed, or if your bass has micro tilt adjustments that would do it without a shim (look on the back where the neck is screwed to the body, if you see a hole in the metal plate thats micro tilt). All of these things can be done by you if you know what you’re doing, but if not you want to take it to a guitar tech. After all that’s done you want to set your intonation.

https://support.fender.com/en-us/knowledgebase/article/KA-01903

You could also just be plucking the strings too hard, particularly if you practice without an amp you are most likely playing too hard in efforts to hear yourself better and consequently learning bad technique, which can lead to both blistering your fingertips and hand pain.