Insight on next steps after renting first property

[Jay Len]

Hi all, in the market for my first home and have a few prospects in sight. Hoping to close on one within the next coming weeks. I’m a 23M earning ~75k and approved for 400k. I’m planning on buying close to my approval amount and living in the property for the first year then planning on renting it out. My question lies in acquiring my second property. Will it be difficult to qualify for another mortgage if my income only increases roughly ~5%? How much time will I need to rent out the property for in order to show the mortgage company I’m trust worthy enough for another mortgage? 
Also is my plan too advantageous to buy a second property within the next 1.5 years after the first one given I can save enough for a down payment? Thanks