The first thing you should do is put it in a proper savings account, not under the mattress or anything like that - at least you'll earn some interest and keep it safe. With 800,000 pesos and this being your first paycheck, investing in something complicated right now is risky; better to first understand how having money in the bank works, what taxes apply in your country, and how much you need for emergencies. Once you've been saving for a couple of months and have a better grip on your cash flow, then you can look into options like investment funds or whatever your bank offers, but for now security and liquidity are your best bet.