Student or Learner
An exhibition was held in my city between May 1st and May 3rd. On May 2nd, I asked my friend to go with me the next day. Sadly, he said that he would be busy then. I went to the exhibition by myself. It's was so dissapointing. Only a few items was put on display and a commision fee was asked. Considering that, I thought better of it. Later that day, My friend texted me to see if it was any good. Then the following thoughts occured to me. It seems if I'd only said"I had to pay to get in", it might sould like I actually paid and saw it. Whereas, if I'd said"I have to pay to get in", such necessity may have been excluded, for the simple present tenses is used to give a general fact. Am I right to think so?
2) "Between May 1st and May 3rd" suggests to me that it was only on on May 2nd. I think "From May 1st to May 3rd" would be better.
3) In order to explain better that there was an entrance fee, I would suggest "I would have to pay to get in" or "I would have had to pay to get in". You're right that saying "I had to pay get in" suggests that you actually went.
4) The way you have written it, I actually thought that you had seen the exhibition, until I reached "Considering that, I though better of it". This is because you said "I went to the exhibition by myself. It was so disappointing. Only a few items were on display." All of those sentence suggested to me that you had seen the exhibition.
My suggestion for the whole paragraph would be:
An exhibition was held in my city from May 1st to May 3rd. On May 2nd, I asked my friend if he would like to go with me the next day, but unfortunately he told me he would be busy that day. I decided to go alone but I discovered that I would have to pay an entrance fee and that there would only be a few items on display. I was very disappointed and consequently, I thought better of it.