How to start playing over the table(OTB)?

Do you mean just playing on a real board?

Do you own a real chess set?

Do you own a chess clock?

Kinda, Yes, No

Well, I know nothing about you or where you live.

Where I live, people get together once a week at the public library to play. They welcome new players.

You can play during lunch at work.

Or if you are still in school, there are often clubs.

Play with friends or family using a real board + clock (digital if possible).

Depending upon wether you mean playing official competitions or just playing home, in the garden, etc, you may want to consider:

In all cases:

Purchase a chess board, preferably "size 5" and the related chess set. Then well, without a clock, it's not really chess, for many reasons that should be obvious if you think about it.

In the case you want to compete, get rated etc:

Join a chess club that is affiliated to a chess federation. Then talk with the people there (or talk before joining), and see what is available for competitions around where you live, or even further if you want and can afford the travels and the accommodations.