I would use Skyscanner or Google flights. You can search from multiple airports to see which one is the most affordable. Are you willing to fly from a further city? Could be wroth it.

Malaysia itself is very organized imo and most cities have a central bus terminal where you can buy the day of or next day tickets. You can also ask locals how to get to another town in more rural areas especially on Borneo. There are also very affordable domestic flights offered.

Skycanner for flights

1. pick your destinations and time frame. We spent 2 weeks and did, KL, cameron highlands, ipoh, georgetown (was going to do langkawi but cancelled and added extra time in georgetown and KL) can also look into tioman islands and other places

2. buses work fine , flights are good too. for buses, 12go asia

Place to look for flights:

1. Skiplagged for simple searches

2. ITA Matrix for more complex searches

Places to look for accommodation:

Hostels: Hostel world

Check out airbnb and google hotels as well

Website for planning land travel in Malaysia: Rome2Rio

Let me know if you have any questions

Things are pretty affordable in malaysia atleast comparing to romania, see this numbeo comparison.
I've seen places that only take cards and no cash and in some bus terminals, i've seen counters only taking cash in my trip, expect both. Taxi and public tranport seems super cheap, I think it's because of the low fuel prices. It's a great country for traveling in a budget.

It's nice that you want to travel far - but why don't you start with a more "familiar" environment, especially if you plan to travel solo? Like a trip in the EU - or if you want to be able to travel cheaper and in a more "demanding" environment that yet feels familiar, then the Balkans.

You should at least know if you can enjoy such a travel before going all the way to Malaysia.

Malaysia is great! We visited last year with our toddler. The people are friendly, almost everyone speaks English, it’s affordable and pretty safe and clean - compared to some other countries in Asia I visited. So I think it’s a good choice for your first time in Asia.

I usually start planning a trip by looking at organized tours to the country, reading their day to day programme, and writing down the things that appeal to me. Those places I label on Google maps. Then I look at the distances between them and decide if I visit them from one ‘base’ and where that base should be, or if I will stay in several areas. Then start looking for accommodation through Booking or Airbnb. Make sure you check reviews.

In Malaysia, we stayed in Kuala Lumpur for 6 nights, then flew to Penang. There we first stayed in Batu Feringhi for some beach days (although the beach wasn’t great), then in George Town for 5 nights. Then flew back to Kuala Lumpur, took a Grab to Malacca and stayed there for 3 nights. It was perfect for us, as this was quite a slow pace which gave us the chance to adapt to our toddler’s needs and rhythm. I think for a first time traveler it’s also wise to take some more time in each place. Give yourself the chance to settle.

Transport in Malaysia is easy - download the Grab app (like Uber).

For flights, we manually added a stopover in Abu Dhabi for 2 nights. This saved us a lot of money!

this is the place to find budget flights.

if you are trying to plan the cheapest way right now would be separate tickets from Romania to Istanbul, then Istanbul SAW to Kuala Lumpur on Air Asia. Even better if you have friends or relatives in Istanbul you can occasionally stay with.

Make sure you hit up Penang at some point. Their street food scene might be one of the best anywhere. I could walk five minutes in any direction from my hotel and hit up a night market or food court with amazing food.

I've only spent a bit of time in Malaysia - on my way back from a much longer stay in Indonesia... so... only in Kuala Lumpur, as that is all I got to see.

There is a place at the foot of the famous Petronas Towers that sell the most massive oysters I have ever seen. They are farmed, and are two-or-three bites, not just one slurp.

The Chinese market is pretty cool. There is some occasional weird tension between the Malay and Chinese populations.

The city trains are excellent.

The "hotel" (backpackers really) where I stayed had a bunch of holes in the wooden walls and graffiti inside the top draw of the dresser warning about one past/present employee who was apparently a peeping tom... it is some old British era hotel.

I liked KL in general and would go back. (I'd also like to see more of the country)

Go to YouTube and search for Malaysia travel videos