I worked at a gasoline stand station because there is one near my house, and it seemed like easy.

I think it should be:
"seemed like a (noun)"
"seemed (adjective)"
Easy is an adjective, so "it seemed easy." You could also say "it seemed like an easy job" because "job" is a noun.

However, it iwas hard for me to work there.

You don't work there anymore, so this should be past tense.

I always had to stand outside anyll the time.

Added to the situation, there is a fewwere few customers (OR "there weren't many customers"), so I was so bored.

few = 少ない
a few = 数人

I had worked there for a year, and my next job is delivery ofing pizza.

I have worked at the pizza place since quitting the gasoline standmy job at the gas station.

I will do my best here by the timeuntil then.

I worked at a gasoline stand station because there is one near my house, and it seemed like an easy job.

Some other synonyms here: https://en.wikipedia.org/wiki/Filling_station
It sounds like "gasoline stand" is correct as a translation of the Japanese, but I haven't really heard it used elsewhere.

I always had to stand outside anytime.

Or: "I had to stand outside all the time."
"Always" and "all the time" mean the same thing, so you don't need both.

Added toTo make the situation worse, there is awere few customers, so I was so bored.

"A few" is used more in place of a number, whereas "few" is used more to indicate how little of something there is. This might be helpful: https://dictionary.cambridge.org/us/grammar/british-grammar/little-a-little-few-a-few

I had worked there for a year, and my next job is delivery ofing pizza.

I have worked at the place since quitting the gasoline stand station.

I will do my best here byfor the time-being.