Can't put curses in the middle of a word

Why cant i put the cursor in the middle of a word it just goes in front or at end and why is my iphone 8 compared to my 6-5-4-3-1 were spelling corrections says No suggestions or gives me words that arnt even close. I read to tap in body of message but sometimes i just want to change 1 letter in a search and unless i stop to check each word when typed and letter I want to remove is at the beginning i have to erase the whole question back to the point i need to fix

[Edited by Moderator]