Sick Betta?

Does he look sick? I just got him a couple weeks ago and hes active and the tank is fine and all is measured out to what is supposed to but I got him from petco and I noticed that he has some red on him but not entirely sure if he is fine? A youtuber mentioned that remarks can be a bad thing..but hes just got into a larger tank and hes always active and interested in food, doesnt show any weird signs. His colors are coming in great but I dont know and want to be a responsible fish owner to make sure hes not sick. No his back is not bent, he just thought I was feeding him

ɪ ᴄᴀɴᴛ ᴛᴇʟʟ ɪғ ʜᴇ ɪs ʜᴇᴀʟᴛʜʏ ᴏʀ ɴᴏᴛ ғʀᴏᴍ ᴛʜᴇ ᴘɪᴄᴛᴜʀᴇs, ɪs ɪᴛ ᴘᴏssɪʙʟᴇ ᴛᴏ ɢᴇᴛ ᴀ ᴄᴏᴜᴘʟᴇ ᴍᴏʀᴇ, ʟᴇss ʙʟᴜʀʀʏ sɪᴅᴇ ᴘɪᴄᴛᴜʀᴇs? Aɴᴅ ᴀ ғᴜʟʟ ᴘɪᴄᴜᴛʀᴇ ᴏғ ᴛʜᴇ ᴛᴀɴᴋ ᴡᴏᴜʟᴅ ᴀʟsᴏ ʙᴇ ʜᴇʟᴘғᴜʟ.

sᴏᴍᴇ ǫᴜᴇsᴛɪᴏɴs,
ʜᴏᴡ ʙɪɢ ɪs ᴛʜᴇ ᴛᴀɴᴋ?
ᴅɪᴅ ʏᴏᴜ ᴄʏᴄʟᴇ ᴛʜᴇ ᴛᴀɴᴋ?
ᴡʜᴀᴛ ᴀʀᴇ ᴛʜᴇ ᴇxᴀᴄᴛ ᴡᴀᴛᴇʀ ᴘᴀʀᴀᴍᴇᴛᴇʀs?
ɪs ᴛʜᴇʀᴇ ᴀ ғɪʟᴛᴇʀ ᴀɴᴅ ʜᴇᴀᴛᴇʀ, ᴀɴᴅ ᴡʜᴀᴛ ɪs ᴛʜᴇ ᴛᴇᴍᴘ?
ᴀʀᴇ ʜɪs sᴄᴀʟᴇs ᴘɪɴᴇᴄᴏɴᴇᴅ ᴏᴜᴛ? ɪғ sᴏ, ʜᴇ ᴄᴏᴜʟᴅ ʜᴀᴠᴇ ᴅʀᴏᴘsʏ.

sᴏᴍᴇᴛɪᴍᴇs ʙᴇᴛᴛᴀ ғɪsʜ ᴄᴀɴ ɢᴇᴛ sᴛʀᴇssᴇᴅ ᴡʜᴇɴ ᴛʜᴇʏ ᴀʀᴇ ᴍᴏᴠᴇᴅ ɪɴᴛᴏ ᴀ ɴᴇᴡ ᴛᴀɴᴋ ᴛʜᴀᴛ ɪs ɴᴏᴛ ᴄʏᴄʟᴇᴅ/ʜᴀs ʙᴀᴅ ᴡᴀᴛᴇʀ ǫᴜᴀʟɪᴛʏ.