I am no good player.. but what a bass player need to adhere to in order to be good in a band ( or playing together with another person ) is to count count count in your heart ( or softly, anyway, nobody can hear, lah )..
When I play certain songs especially those which has long repetitive notes, I tend to get lost when the next bar or note came it. So I start to count 1,2,3,4,5,6,7,8.. 2,2,3,4,5,6,7,8 etc... something like that..
As for sounds, effects, really waste money. I buy I sell.. each time I lose some. End up back to square one - a multi effect same as what I got the first day... LOLX
Important is actually, in my short playing experience, to do a good quality recording of your band playing, then listen to it over and over again. Last time I thought deep bass sounds really cool ( I mean, bass guitar should sound bassy right ? )
Wrong.. actually Mid and Highs are as important. There is a free effect you can do, which is your tone knobs on your bass. Try figure the sounds out during play.. you will realize its also a very good and cheap ( free ) effect..