What is my Steam Level?
Your Steam Level is a summary of your badges and shows off your trading card collection and participation in Steam events. Each badge earned increases your XP, and every 100 XP gives you an added Steam Level (at least to start).
https://psteamcommunity.yuanyoumao.com/tradingcards/faq

You do not receive XP directly from playing games but for creating badges for games (or seasonal badges).

Read FAQ: https://psteamhelp.yuanyoumao.com/en/faqs/view/1F74-BE45-3AAC-1B47
This community guide might also be of use: https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3268851867

How do I increase XP on my profile to level up?

There are a number of ways to increase your profile level on Steam. These include:

• Purchasing games
  
• Earning badges
  
• Crafting badges
  
• Upgrading badges

For more information about your Steam level and how to increase it, please see the Trading Cards FAQ.

Learn more about Steam Levels and XP here:

https://psteamhelp.yuanyoumao.com/en/faqs/view/1F74-BE45-3AAC-1B47

引用自 InspireJr：

I`m not getting xp on Steam

Hello for all I`m new here I have upgrade account with 5$ and I`m playing competitive casual Wingman but I`m still not getting xp on steam can anyone give me some advice how to get xp Thank You

Playing CS2 doesn't increase your Steam level.

You do not recieve xp from playing games on Steam you get them from crafting badges for games on Steam like crafting the CS2 badge Medieval II: Total War badge, you craft badges with trading cards, trading cards drop when playing games with Steam trading cards you should get all the card drops for the game in about by the first 3 hours of playtime on the game after this you will recieve no more card drops for the game but you can use booster packs to get 3 card drops for the game each. Each badge you craft on Steam gives 100 xp and can be crafted 5 times for each game and an additional sixth foil badge which is rarer than the 5 standard badges. Foil badges can be crafted with foil badges which are much rarer to drop.