The main task is to optimize it for the keyword "Travel Agency Company"

Probably don't need to optimize for "company" since it's a very generic term.

BTW - Pro Members [webmasterworld.com] can request site reviews in the WebmasterWorld Supporters forums where you can post the link to your site and get feedback.

Recently got a job as an SEO Officer

I'm a newbie in handling things like this and will need a head start from the experts

hmm, curious as to how and why you were recruited then... I don't want to be mean, I am just teasing :)

The main task is to optimize it for the keyword "Travel Agency Company" both local and Worldwide

This will be rough to optimize for such generic keywords, this is a niche which is ultra competitive, may be too much competitive, and the fact that Google is also in the business of travel, makes it nearly impossible to rank for such words, in my opinion. May be try to be less generic, and focus on destinations.

The site needs to provides information about "traveling", and not just prices and offers. This mean for example, information about the destinations, why to go there, when, how, what to see/visit, if there are special requirements to visit this destination (visa, vaccines, etc...), local things (cultural events, foods, monuments...).

Also consider hosting a forum where people are exchanging their experience about their travels, or seeking advices.

Additionally, from a technical point of view, be sure the site is fast, as fast as possible, low TTFB, fast First Paint, use HTTP/2 (meaning HTTPS too), be mobile friendly.

The main task is to optimize it for the keyword "Travel Agency Company" both local and Worldwide

No it isn't. (OK, it's maybe what you were told by your superior but they just proved they have very little idea when it comes to websites.)

As was mentioned above, the phrase you quoted is pretty useless when it comes to searches and interest and probably out of reach for your company if they are hiring an SEO with little knowledge (not to be insulting, just practical).

If you can, go and talk to whoever deals with the money side of your company. Where does it make most of its money? Which type of clients? From where? Doing what? Looking for what? You say you want 'worldwide' rankings but what good does that do a travel agency based in Plumpton, Ohio, when a Malaysian website viewer is looking for a last-minute break at a local beach?

Then go and sit down with whoever deals with your clients on a personal level (either face-to-face or on the phone). Ask them what they talk about most of the time with those clients and listen to them without interrupting or projecting your own views. Take notes. Talk to as many people as possible.

Then you should have an idea of some niches where your company already has a foothold and the kind of questions people in those niches are looking to have answered before they travel.

Integrating information and answers to those questions into your web presence (whether website or other media) will make a tremendous start for your SEM career, especially since your corporate competition is probably just as clueless as your own superiors and just wants a website that looks good so they can show it off to colleagues at conferences (I'm not joking here) and one which ranks for generic but ineffective keywords.

(These are the kind of keyword lists generated by SEO sales departments of ISPs to prove their dubious worth. Look you are ranking #1 for 'best small travel agency in Adams County'!)

Follow all the Google on-Page rules which are more than 200 - Half work is Done
Now Create Good Quality of Links only from Travel Websites
Along with it Go with the Content Marketing