The pay to play websites such as Voices123, Voices.com, Mandy, Fiverr and Upwork are a good resource for voice actors - also Casting Call Club is a good place to go for character voice work but most of the gigs there are not paying jobs, just 'for fun'. The problem with all of these is that you have to 'Pay to Play' to receive any benefit from them.
I am a paid member of all the above except for Mandy.com and the most frustrating thing is receiving notifications from Mandy saying that there's a job posting but I can't be involved because I don't 'pay to play'. I keep meaning to go and unsubscribe from Mandy but then I wouldn't see what was going on there so I just let the emails keep coming in to tell me about jobs I can't audition for.
I have received job offers on the platforms above and some the rates are extremely low-ball but some are pretty decent.
On Fiverr, you have to make sure you optimise your Gigs so that they encourage people to buy your voice service. Be careful, there's some very odd people out there and you have to be choosey about who you say 'yes' to and what the job is. If your gut instinct says there's something odd, go with your gut!
On Upwork, you can also post Gigs/Projects so make sure you do that with all the correct information and showcase your best voice demos.
On Voice123, you will receive emails showing there's a job posted and you can go and audition for it. There's a lot of auditions on that platform and even if you don't get awarded any jobs, it's a good place to practice your audition skills.
On Voices.com you will receive emails showing there's a job posted so you can go and audition for it if you feel you are suited to that job. Again, it's a good place to get your audition skills up to scratch and a good place to see multiple script styles.
Casting Call Club is a really good place to practice character voices because there's lots of opportunities to audition for different roles. Bear in mind, most of these aren't paying jobs and it's totally up to you whether you choose to audition with the possibility of getting a part for no pay. I like it because I'm trying to learn character voicing so it's providing me with lots of different characters to try out for. I think that so far I'm best suited to the evil/mean character.