Hi, Ringo, and welcome to WW.
First, congratulations on finishing your first novel! That's a great achievement and definitely worthy of pride.
As to your question, I think only you can decide whether to sub your novel to agents/publishers. There are various options, though.
1. Put the novel away for, say, three months. Then read it through as a reader and see how it strikes you and make your decision then.
2. Show it to someone whose opinion you respect - or pay for an editorial report. This might throw up questions, or it might confirm that you're ready to submit.
3. Throw caution to the wind and submit now. Choose a select list of agents and look on it as an experiment. Send out to, maybe, five or fewer and just see what comes back. Maybe they'll give you some feedback. Maybe they'll sign you up!
4. (Combined with (1) - Put the novel aside and write another. This may put a new perspective on the first one.
I don't think there are any 'right' answers. Just the one that feels right for you. Good luck with whatever you decide.
Susiex