I've seen hundreds of different music students come through the college where I used to work over the years, and there really were some very different types. Some had learned from books and knew all the theory, could play every single clever scale, in any key and were technically brilliant - AND - totally unmusical and 100% unable to play in a scratch band with others. At the other end we had others who knew about root, fourth and fifth, and could play crotchets (4th notes) in time with the others, and 'feel' where the chord changes came. As long as they knew the note position to start on they were fine. Others had learned patterns, as distinct from riffs, that they could use in a variety of song styles. Others could only play from sheet music, others couldn't read sheet music at all. As a teacher, I discovered the theory we learnt about learning styles was spot on, and everyone did have their own way of learning. The problem was finding the best one for each person.
Talent wise, it was very different. Some could hear a popular song and 'know' what the next note would be, and be able to play it. Others seemed to have no prediction ability at all. One guy could sight read stuff that I really struggled with. He couldn't, however, play a note without the music. In the studio or at a soundcheck, somebody would yell - "bit of bass please" and if he didn't have any music out yet, he could play nothing at all. He was great in a reading band, but did not remember anything he had played - even when he had played it 20 times already.
One guy heard the Stevie Wonder track Sir Duke just once, and instantly played the signature riff in it perfectly.
Some people instinctively play the right pattern for a jam - some just cannot. Some can improvise around a chord sequence, some cannot. Some are sloppy with their timing, others very rigid and inflexible.
You need to find out how good you are by asking people you trust.
When I joined the tribute band I am in, I never gave any thought to if I could sing and play at the same time. Course I can, I thought. After nearly 40 years, I discovered I had to work really hard to learn the songs so I could play exactly the same thing every show automatically, while my brain tackled the four part harmony lines. Early on I discovered I was a bass version of George Benson - my singing suddenly switched to the notes I was playing on the bass. It took amazing effort to split my brain in two. Now my bass playing is largely automatic, but in two songs, where what I play is quite hard, it's very easy for my voice to switch off while my brain switches to 100% on the bass.
My own feeling (for me) is that the best practice comes from playing songs you only vaguely know, so you perhaps have an idea of what the bass plays, but you have to basically make it up on the spot. You perhaps know the song very well - you think. I often get roped into things with little or no rehearsal. Village People's In the Navy - I've heard this for years and years, but never ever properly listened to it. I could visualise the chords, but what is played I discovered is not what I thought. That old 70s song - Disco Inferno (two slightly different bass lines) and Burn Baby Burn - wears your fingers out with a repetitive bass line. Then you get Michael Jackson's Billie Jean is another good one that may be half in your head.
I also cannot do reggae. Something in my head just messes it up unless I really, really concentrate - relax for one second and I'm on the wrong beat!
Find somebody you trust and ask them to be honest!