If you're not 100% sure on the tow capacity, check out the 2020 TrailerLife tow guide. It's really detailed. It shows even how something like your bed size could affect your tow capacity. I'll attach a link, but you can also find it by Googling it.
https://mtboats.com/towing/2020towingguide.pdf
The rule of thumb I go with is no more than 70% of tow capacity for trailer size. My truck has a tow capacity of 10,050. We settled on a 35ft Prowler that's 7,000 lbs. It's the best towing rig I've had. We've been in mountains of Pennsylvania and NY and have had no issues. The truck handled the worst climbs; Bloss mountain/PA, Rt 12 Utica NY.
I have some points I stick to:
1) Tires: Must have good tires. Those brand-new China bombs came off. Despite hearing how you don't need balancing, I always have them balanced for the best possible ride.
2) Air pressure: I check trailer and truck before every trip. If they stray more than a few pounds, I'll top them off.
3) WDH: I have a quality WDH. It's dialed in perfect. My bars are sized for the trailer and the torsion is set properly.
4) Speed: I stick to around 63-65 MPH on the expressway. Tow-Haul is always on. I use cruise control a lot. I do occasionally flirt with 70mph, but mostly downhill.
5) Monitor conditions: Slow down for poor roads or weather. I have had to pull off and wait for a storm to blow though.