What are the precautions to be taken when using condom for first time in life?

Generally none: Some men can be sensitive or even allergic to either latex or spermicides, but this is rather uncommon. (would cause some redness & skin irritation the next day). You may wish to get a few different sizes, styles, textures, flavors etc. To experiment and see which you and your partner prefer. Have fun!

Nothing special: Just make sure you are not allergic to latex; most condoms are made of non-latex material; be sure yours is. Be aware of slippage of the condoms during intercourse; if slipped may consider "morning-after" pills if pregnancy not desired.

Sizing/no reuse: There are many products available and you need to find one that fits. It should be tight enough to prevent leakage, but loose enough you are not uncomfortable. If you have a latex allergy, use other types. Never reuse a condom unless you are okay with it failing.